As previously announced, on April 13, 2026, Leggett & Platt, Incorporated, a Missouri corporation (“Leggett & Platt”), entered into an Agreement and Plan of Merger (the“Merger Agreement”) with Somnigroup International Inc., a Delaware corporation (“Somnigroup”), and Sparrow Unity Corporation, a Missouri corporation and a direct, whollyowned subsidiary of Somnigroup (“Merger Sub” and together with Somnigroup, the “Somnigroup Parties”), pursuant to which, subject to the terms and conditions of the MergerAgreement, Merger Sub will merge with and into Leggett & Platt (the “Merger”), with Leggett & Platt surviving the Merger as a direct, wholly owned subsidiary of Somnigroup. Subject to the terms and conditions of the Merger Agreement, at the effective time of the Merger (the “Effective Time”) and by virtue of the Merger, each share of commonstock, par value $0.01 per share, of Leggett & Platt (“Leggett & Platt common stock”) issued and outstanding immediately prior to the Effective Time (other than the Leggett &Platt Cancelled Shares and Dissenting Shares, each as defined in the Merger Agreement), will be converted automatically into the right to receive 0.1455 (the “Exchange Ratio”)shares of common stock, par value $0.01 per share, of Somnigroup (“Somnigroup common stock”) and, if applicable, cash in lieu of fractional shares (the “Merger Consideration”). The Exchange Ratio is fixed and will not be adjusted to reflect price changes prior to the closing of the Merger. Somnigroup common stock is listed on the New York StockExchange (the “NYSE”) under the trading symbol “SGI,” and Leggett & Platt common stock is listed on the NYSE under the trading symbol “LEG.” Based on the closing price ofSomnigroup common stock on the NYSE on April 10, 2026, the last trading day before the public announcement of the Merger Agreement, the Exchange Ratio representedapproximately $11.36 in value for each share of Leggett & Platt common stock. This amount represented a premium of approximately 13.7% to the closing price of Leggett & Plattcommon stock of $9.99 on the NYSE on April 10, 2026. Based on the closing price of Somnigroup common stock on the NYSE of $74.82 on July 7, 2026, the latest practicabletrading day before the date of this proxy statement/prospectus, the Exchange Ratio represented approximately $10.89 per share in value for each share of Leggett & Platt commonstock. If a proceeding is commenced by the U.S. Department of Justice or Federal Trade Commission under any applicable U.S. federal competition law seeking to prohibit or delaythe Merger, Leggett & Platt will declare and pay to holders of Leggett & Platt common stock as of immediately prior to the Effective Time a special dividend (the “SpecialDividend”) in an amount equal to 6% of the volume-weighted average price of Leggett & Platt common stock for the 30 trading days ending immediately prior to the date and timeat which the closing of the Merger occurs (the “Closing Date”), multiplied by the number of shares of Leggett & Platt common stock outstanding immediately prior to the EffectiveTime, multiplied by a fraction equal to (i) the number of calendar days elapsed from the commencement of such proceeding through the Closing Date, divided by (ii) 365. NoSpecial Dividend will be payable if (i) the Closing Date does not occur, (ii) no such proceeding is commenced or (iii) the Closing Date occurs on or prior to the date any suchproceeding is commenced. The value of the consideration paid to Leggett & Platt shareholders will fluctuate with changes in the market price of Somnigroup common stock. We encourageyou to obtain current market quotations of Somnigroup common stock, given that the Merger Consideration is payable in Somnigroup common stock. Based on the number of outstanding shares of Leggett & Platt common stock (including shares of Leggett & Platt restricted stock) on the record date of July 6, 2026 for theLeggett & Platt Special Meeting (as defined below), we anticipate that Somnigroup will issue approximately 19,872,203 shares of Somnigroup common stock in connection withthe Merger. Upon completion of the Merger, based on the number of outstanding shares of Leggett & Platt common stock and Somnigroup common stock as of the record date, theformer Leggett & Platt shareholders will own approximately 8.6% of the outstanding shares of Somnigroup common stock and current Somnigroup stockholders will ownapproximately 91.4% of the outstanding shares of Somnigroup common stock. In connection with the Merger, Leggett & Platt will hold a virtual special meeting of Leggett & Platt shareholders (the “Leggett & Platt Special Meeting”) to consider andvote on: (1) a proposal to adopt the Merger Agreement (the “Merger Proposal”); (2) a proposal to approve, by non-binding, advisory vote, the compensation that will or maybecome payable to Leggett & Platt’s named executive officers that is based on or otherwise relates to the Merger (the “Merger-Related Compensation