Roche Holdings said that it wants to increase its stake in its Japanese partner Chugai Pharmaceutical to 59.9 percent from the current 50.1 percent.
The Swiss pharma group said it will offer Chugai shareholders 1,730 yen per share, which reflects an 11.7 percent premium over the share's closing price on May 21, 2008.
"We intend to increase our stake because we believe in both the long-term potential of the Japanese market and in the strategic importance of this successful partnership," said chairman and former group CEO Franz Humer.
Roche said the transaction is based on the group's right to increase its stake to 59.9 percent at any time after the 5th anniversary of the alliance which was formed in October 2002. Since the start of their cooperation, Chugai has launched a number of Roche drugs in Japan including colorectal cancer Avastin and lung cancer drug Tarceva.
In November 2007, rheumatoid arthritis drug Actemra was filed in the U.S. and Europe as the first Chugai medicine that Roche is developing for worldwide commercialisation.
Shares of Chugai rose 3.3 percent on Friday in reaction to news of Roche's plan to increase its stake.