Canada-based drugmaker Valeant Pharmaceuticals International is reportedly planning to buy US firm Salix Pharmaceuticals.
Bloomberg reported sources as saying that Valeant has started discussions with the advisers for acquiring Salix.
Irish drugmaker Shire has also reportedly expressed an interest to purchase Salix, which produces drugs to treat ulcerative colitis and travellers' diarrhoea.
The US firm has a market value of around $9bn, after its share increased by 5% to $140.47 in New York trading, reported the news publication.
Representatives of all firms declined to comment on the latest development.
Salix was established with an aim to develop products to treat gastrointestinal disorders (GI), and the company has licensed, developed and marketed products to treat GI problems over the last 20 years.
In November 2014, Salix and Pharming Group introduced Ruconest (C1 esterase inhibitor [recombinant]) 50IU/kg in the US, a treatment developed to treat acute angioedema attacks in adult and adolescent patients with hereditary angioedema (HAE).
In November 2013, Salix entered a merger agreement to acquire Santarus for $2.6bn as part of its strategic plans to boost its portfolio of drugs with a complementary set of products.
At the end of last month, Valeant signed a stalking horse agreement to acquire certain assets of US-based Dendreon for $296m in cash.
In August 2013, Valeant announced that it will acquire eye health company Bausch + Lomb for $8.7bn in cash.
