Salix would be the largest purchase ever made by Canada-based Valeant, whose growth has been fueled by acquisitions and cost-cutting. The acquisition would offer solace for dealmaking Valeant Chief Executive Michael Pearson, whose hostile bid for Allergan Inc (AGN.N) failed last year. It would also boost investor Bill Ackman, who announced last week he had bought a more than $3 billion stake in Valeant after having worked with the company on the Allergan bid.