Canada-based Valeant Pharmaceuticals International has increased its offer to an enterprise value of $15.8bn from $14.5bn to acquire Salix Pharmaceuticals.
Both firms have entered an amendment to their agreement and plan of merger announced in February.
Under the amendment, Valeant will pay an increased price of $173.00 per share to Salix over the original price of $158.00 per share. The revised offer price will add around additional $1bn cash to Salix stockholders.
Valeant Pharmaceuticals International chairman and CEO Michael Pearson said: "This revised offer provides Salix shareholders with all-cash at a significant premium and the certainty to close by 1 April."
Valeant has increased the offer price, as specialty healthcare firm Endo Internationl proposed to pay $175 per Salix share earlier this month.
Endo’s proposed negotiated cash and stock transaction involves acquiring all of the outstanding shares of Salix common stock for per share consideration of 1.4607 shares of Endo common stock and $45 payable in cash at closing.

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By GlobalDataSalix Pharmaceuticals boar chairman and acting CEO Thomas D’Alonzo said: "We are pleased that the enhanced offer price recognizes the value of Salix as the leading gastrointestinal specialty pharmaceutical company and delivers to our stockholders all cash consideration in the near future."
Holding a significant share in gastrointestinal market, Salix produces 22 products, including prescription brands such as Xifaxan, Uceris, Relistor, and Apriso.