UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

Tender Offer Statement under Section 14(d)(1) or 13(e)(1)

of the Securities Exchange Act of 1934

SOUTHWEST GAS HOLDINGS, INC.

(Name of Subject Company)

IEP UTILITY HOLDINGS LLC

ICAHN ENTERPRISES HOLDINGS L.P.

ICAHN ENTERPRISES L.P.

ICAHN ENTERPRISES G.P. INC.

BECKTON CORP.

CARL C. ICAHN

(Names of Filing Persons) (Offerors))

Common Stock, par value $1.00 per share

(Title of Class of Securities)

844895102

(CUSIP Number of Class of Securities)

Jesse Lynn, Esq.

Icahn Associates LLC

16690 Collins Avenue, Suite PH-1

Sunny Isles Beach, FL 33160

(305) 422-4100

(Name, Address, and Telephone Number of Person Authorized to Receive Notices and Communications

on Behalf of Filing Persons)

CALCULATION OF FILING FEE

Check the appropriate boxes below to designate any transactions to which the statement relates:

Check the following box if the filing is a final amendment reporting the results of the tender offer.  ☐

If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:

This Tender Offer Statement on Schedule TO relates solely to preliminary communications made before the commencement of a planned tender offer by IEP Utility Holdings LLC, a Delaware limited liability company and an affiliate of Icahn Enterprises L.P. (“Icahn Enterprises”), for any and all of the outstanding shares of the common stock, par value $1.00 per share (the “Shares”), of Southwest Gas Holdings, Inc., a Delaware corporation (“SWX”).

NOTICE TO INVESTORS

THE PROPOSED TENDER OFFER MENTIONED ABOVE HAS NOT YET COMMENCED. THIS COMMUNICATION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT A RECOMMENDATION, AN OFFER TO PURCHASE OR A SOLICITATION OF AN OFFER TO SELL SHARES. AT THE TIME THE TENDER OFFER IS COMMENCED, AFFILIATES OF ICAHN ENTERPRISES WILL FILE A TENDER OFFER STATEMENT AND RELATED EXHIBITS WITH THE SECURITIES AND EXCHANGE COMMISSION (THE “SEC”) AND SWX WILL FILE A SOLICITATION/RECOMMENDATION STATEMENT WITH RESPECT TO THE TENDER OFFER WITH THE SEC. STOCKHOLDERS OF SWX ARE STRONGLY ADVISED TO READ THE TENDER OFFER STATEMENT (INCLUDING THE RELATED EXHIBITS) AND THE SOLICITATION/RECOMMENDATION STATEMENT, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT STOCKHOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SHARES. IF THE TENDER OFFER IS COMMENCED, THE TENDER OFFER STATEMENT (INCLUDING THE RELATED EXHIBITS) AND THE SOLICITATION/RECOMMENDATION STATEMENT WILL BE AVAILABLE AT NO CHARGE ON THE SEC’S WEBSITE AT WWW.SEC.GOV. IN ADDITION, IF THE TENDER OFFER IS COMMENCED, THE TENDER OFFER STATEMENT AND OTHER DOCUMENTS THAT ARE FILED BY ICAHN ENTERPRISES (OR ITS AFFILIATES) WITH THE SEC WILL BE MADE AVAILABLE TO ALL STOCKHOLDERS OF SWX FREE OF CHARGE UPON REQUEST TO THE INFORMATION AGENT FOR THE TENDER OFFER. THE INFORMATION AGENT FOR THE TENDER OFFER WILL BE HARKINS KOVLER, LLC, 3 COLUMBUS CIRCLE, 15TH FLOOR, NEW YORK, NY 10019, TOLL-FREE TELEPHONE: +1 (800) 326-5997, EMAIL: SWX@HARKINSKOVLER.COM.

Forward-Looking Statements

The attached letter to stockholders may contain certain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, many of which are beyond our ability to control or predict. Forward-looking statements may be identified by words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” “will” or words of similar meaning and include, but are not limited to, statements about the expected future business and financial performance of Icahn Enterprises L.P. and its subsidiaries. Actual events, results and outcomes may differ materially from our expectations due to a variety of known and unknown risks, uncertainties and other factors. Forward-looking statements in this document include, without limitation, statements regarding the planned completion of the offer. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated, including, but not limited to, risks and uncertainties related to: statements regarding the anticipated benefits of the transaction; statements regarding the anticipated timing of filings and approvals relating to the transaction; statements regarding the expected timing of the completion of the transaction; the percentage of SWX’s stockholders tendering their shares in the offer; the possibility that competing offers will be made; the possibility that various closing conditions for the transaction may not be satisfied or waived, including that a governmental entity may prohibit, delay or refuse to grant approval for the consummation of the transaction; the effects of disruption caused by the transaction making it more difficult to maintain relationships with employees and customers; stockholder litigation in connection with the transaction resulting in significant costs of defense, indemnification and liability; and other risks and uncertainties discussed in Icahn Enterprises’ filings with the SEC, including the “Risk Factors” sections of its Annual Report on Form 10-K for the year ended December 31, 2020 and the subsequent quarterly reports on Form 10-Q, as well as the tender offer documents to be filed by affiliates of Icahn Enterprises and the Solicitation/Recommendation Statement to be filed by SWX. Icahn Enterprises does not undertake any obligation to update any forward-looking statements as a result of new information, future developments or otherwise, except as expressly required by law. All forward-looking statements in the attached letter to stockholders are qualified in their entirety by this cautionary statement.

Item 12. Exhibits

Exhibit (a)(5)(A)

Carl C. Icahn Issues Open Letter to

Shareholders of Southwest Gas

Sunny Isles Beach, Florida, October 20, 2021 — Today, Carl C. Icahn released the following open letter to the shareholders of Southwest Gas Holdings, Inc. (NYSE: SWX).

“John Hester lives in the right city – because he really seems to like playing roulette. What bothers us is that he is doing it with our money.” – Carl C. Icahn

Investor Contacts:

Harkins Kovler, LLC

Peter Harkins / Jordan Kovler

(212) 468-5390 / (212) 468-5384

pharkins@harkinskovler.com / jkovler@harkinskovler.com

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CARL C. ICAHN

16690 Collins Avenue, Suite PH-1

Sunny Isles Beach, FL 33160

October 20, 2021

Fellow Shareholders:

This letter serves as a rebuttal to SWX management’s letter dated October 13, 2021. Management’s response to our letter exhibits two things:

WE BELIEVE SHAREHOLDERS ARE FED UP WITH MANAGEMENT’S GUISE AND WILL VOTE FOR OUR FULL SLATE OF DIRECTORS. THE VALUE DESTRUCTION MUST STOP. WE WELCOME ALL SHAREHOLDERS TO EITHER PARTICIPATE IN OUR ANY AND ALL TENDER OFFER AND RECEIVE $75 PER SHARE OR PARTICIPATE IN OUR PLAN FOR LONG-TERM VALUE CREATION TO BE EXECUTED BY OUR BLUE-RIBBON SLATE OF DIRECTORS.

Below are our responses to the statements made in SWX’s disingenuous and misleading letter, which we find insulting to the intelligence of all shareholders. But this is not surprising, given the authors – the SWX board and management team – barely qualify as shareholders. Collectively, they hold well under 1% of the company!

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“We don’t really focus on synergies. We think there may be some of those available. As Karen was mentioning earlier, we’ve got a transition services agreement in place with Dominion of some of the services that were provided to the Questar Pipelines asset, were provided by Dominion. So when that transition services agreement ends, we will have to — or, rather along that path, we will be adding some employees.”

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Shareholder: “Any update on the thinking to perhaps separating Centuri from Southwest in any way?”

CEO: “As the business continues to grow, we believe that, that does tend to incrementally increase what we could call its optionality is the possibility of having a publicly traded equity like you say – like you suggest, a possibility some time down the road. I would say, certainly that is a possibility”

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For all these reasons, we believe our proxy contest and tender offer are in the interest of all stakeholders (except for senior management and the Board of Directors). We urge shareholders to speak to management and the Board and let them know how they feel about management’s recent actions. We urge shareholders to vote for our upcoming slate and decide whether to tender their shares or participate in long-term value creation.

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Additional Information and Where to Find It;

Participants in the Solicitation and Notice to Investors

SECURITY HOLDERS ARE ADVISED TO READ THE PROXY STATEMENT AND OTHER DOCUMENTS RELATED TO THE SOLICITATION OF PROXIES BY CARL C. ICAHN AND HIS AFFILIATES FROM THE STOCKHOLDERS OF SOUTHWEST GAS HOLDINGS, INC (“SOUTHWEST GAS”). USE AT THE ANNUAL MEETING OF STOCKHOLDERS OF SOUTHWEST GAS WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION, INCLUDING INFORMATION RELATING TO THE PARTICIPANTS IN SUCH PROXY SOLICITATION. WHEN COMPLETED, A DEFINITIVE PROXY STATEMENT AND A FORM OF PROXY WILL BE MAILED TO STOCKHOLDERS OF SOUTHWEST GAS AND WILL ALSO BE AVAILABLE AT NO CHARGE AT THE SECURITIES AND EXCHANGE COMMISSION’S (“SEC”) WEBSITE AT HTTP://WWW.SEC.GOV. INFORMATION RELATING TO THE PARTICIPANTS IN SUCH PROXY SOLICITATION IS CONTAINED IN THE SCHEDULE 14A FILED BY CARL C. ICAHN AND HIS AFFILIATES WITH THE SECURITES AND EXCHANGE COMMISSION ON OCTOBER 5, 2021. EXCEPT AS OTHERWISE DISCLOSED IN THE SCHEDULE 14A, THE PARTICIPANTS HAVE NO INTEREST IN SOUTHWEST GAS.

THE SOLICITATION DISCUSSED HEREIN RELATES TO THE SOLICITATION OF PROXIES FOR USE AT THE 2022 ANNUAL MEETING OF STOCKHOLDERS OF SOUTHWEST GAS HOLDINGS.

THE PROPOSED TENDER OFFER MENTIONED ABOVE HAS NOT YET COMMENCED. THIS COMMUNICATION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT A RECOMMENDATION, AN OFFER TO PURCHASE OR A SOLICITATION OF AN OFFER TO SELL SHARES. AT THE TIME THE TENDER OFFER IS COMMENCED, AFFILIATES OF ICAHN ENTERPRISES WILL FILE A TENDER OFFER STATEMENT AND RELATED EXHIBITS WITH THE SEC AND SWX WILL FILE A SOLICITATION/ RECOMMENDATION STATEMENT WITH RESPECT TO THE TENDER OFFER WITH THE SEC. STOCKHOLDERS OF SWX ARE STRONGLY ADVISED TO READ THE TENDER OFFER STATEMENT (INCLUDING THE RELATED EXHIBITS) AND THE SOLICITATION/RECOMMENDATION STATEMENT, AS THEY MAY BE AMENDED FROM TIME TO TIME, WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT STOCKHOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SHARES. IF THE TENDER OFFER IS COMMENCED, THE TENDER OFFER STATEMENT (INCLUDING THE RELATED EXHIBITS) AND THE SOLICITATION/RECOMMENDATION STATEMENT WILL BE AVAILABLE AT NO CHARGE ON THE SEC’S WEBSITE AT WWW.SEC.GOV. IN ADDITION, IF THE TENDER OFFER IS COMMENCED, THE TENDER OFFER STATEMENT AND OTHER DOCUMENTS THAT ARE FILED BY ICAHN ENTERPRISES (OR ITS AFFILIATES) WITH THE SEC WILL BE MADE AVAILABLE TO ALL STOCKHOLDERS OF SWX FREE OF CHARGE UPON REQUEST TO THE INFORMATION AGENT FOR THE TENDER OFFER. THE INFORMATION AGENT FOR THE TENDER OFFER WILL BE HARKINS KOVLER, LLC, 3 COLUMBUS CIRCLE, 15TH FLOOR, NEW YORK, NY 10019, TOLL-FREE TELEPHONE: +1 (800) 326-5997, EMAIL: SWX@HARKINSKOVLER.COM.

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Other Important Disclosure Information

SPECIAL NOTE REGARDING THIS LETTER:

THIS LETTER CONTAINS OUR CURRENT VIEWS ON THE VALUE OF SOUTHWEST GAS SECURITIES AND CERTAIN ACTIONS THAT SOUTHWEST GAS’ BOARD MAY TAKE TO ENHANCE THE VALUE OF ITS SECURITIES. OUR VIEWS ARE BASED ON OUR OWN ANALYSIS OF PUBLICLY AVAILABLE INFORMATION AND ASSUMPTIONS WE BELIEVE TO BE REASONABLE. THERE CAN BE NO ASSURANCE THAT THE INFORMATION WE CONSIDERED AND ANALYZED IS ACCURATE OR COMPLETE. SIMILARLY, THERE CAN BE NO ASSURANCE THAT OUR ASSUMPTIONS ARE CORRECT. SOUTHWEST GAS’ PERFORMANCE AND RESULTS MAY DIFFER MATERIALLY FROM OUR ASSUMPTIONS AND ANALYSIS.

WE HAVE NOT SOUGHT, NOR HAVE WE RECEIVED, PERMISSION FROM ANY THIRD-PARTY TO INCLUDE THEIR INFORMATION IN THIS LETTER. ANY SUCH INFORMATION SHOULD NOT BE VIEWED AS INDICATING THE SUPPORT OF SUCH THIRD PARTY FOR THE VIEWS EXPRESSED HEREIN.

THIS LETTER ALSO REFERENCES THE SIZE OF OUR RESPECTIVE CURRENT HOLDINGS OF SOUTHWEST GAS SECURITIES. OUR VIEWS AND OUR HOLDINGS COULD CHANGE AT ANY TIME. WE MAY SELL ANY OR ALL OF OUR HOLDINGS OR INCREASE OUR HOLDINGS BY PURCHASING ADDITIONAL SECURITIES. WE MAY TAKE ANY OF THESE OR OTHER ACTIONS REGARDING SOUTHWEST GAS WITHOUT UPDATING THIS LETTER OR PROVIDING ANY NOTICE WHATSOEVER OF ANY SUCH CHANGES (EXCEPT AS OTHERWISE REQUIRED BY LAW).

FORWARD-LOOKING STATEMENTS:

Certain statements contained in this letter are forward-looking statements including, but not limited to, statements that are predications of or indicate future events, trends, plans or objectives. Undue reliance should not be placed on such statements because, by their nature, they are subject to known and unknown risks and uncertainties. Forward-looking statements are not guarantees of future performance or activities and are subject to many risks and uncertainties. Due to such risks and uncertainties, actual events or results or actual performance may differ materially from those reflected or contemplated in such forward-looking statements. Forward-looking statements can be identified by the use of the future tense or other forward-looking words such as “believe,” “expect,” “anticipate,” “intend,” “plan,” “estimate,” “should,” “may,” “will,” “objective,” “projection,” “forecast,” “management believes,” “continue,” “strategy,” “position” or the negative of those terms or other variations of them or by comparable terminology.

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Important factors that could cause actual results to differ materially from the expectations set forth in this letter include, among other things, the factors identified in Southwest Gas’ public filings. Such forward-looking statements should therefore be construed in light of such factors, and we are under no obligation, and expressly disclaim any intention or obligation, to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

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