Actavis said Tuesday it will pay Forest shareholders $26.04 in cash and a portion of an Actavis share for each Forest share. The total, per-share price of $89.48 represents a premium of about 25 percent over Forest's closing price Friday of $71.39.
Shares of New York-based Forest soared nearly 30 percent to $92.50 in Tuesday morning trading. That's well above the price Actavis offered, a sign that shareholders believe Forest will receive a better offer. U.S.-traded shares of Dublin-based Actavis climbed 7.6 percent, or $14.56, to $206.04.
Actavis was formed in 2012 through a $5.6 billion tie-up between generic drugmaker Watson Pharmaceuticals and Actavis Group. It has grown rapidly through acquisitions, including an $8.5 billion deal it closed last fall to buy another Irish drugmaker, Warner Chilcott.
It offers generic drugs and specialty products in areas like urology and women's health. That portfolio includes the osteoporosis treatment Actonel.
New York-based Forest Labs has been squeezed by generic competition to some of its biggest drugs, including its anxiety and depression drug Lexapro. It also faces the loss of patent protection for Namenda in 2015. The company has launched several new drugs, including Viibryd and the lung disease drug Daliresp, to help make up for those losses.
Forest took an annual loss in fiscal 2012, its first in 15 years, and has faced pressure from billionaire investor Carl Icahn, its second-largest shareholder, according to FactSet.
The company has been working to cut costs under new CEO Brent Saunders, who replaced long-standing leader Howard Solomon last fall. The new leader, backed by Icahn, launched plans to cut about 500 jobs as part of a goal to trim $500 million in costs.
Tuesday's announcement comes a few weeks after Forest completed its own acquisition, a $2.9 billion purchase of Aptalis, a company that makes treatments for gastrointestinal problems and cystic fibrosis.