Roche Holding AG decided against bidding for the almost 40 percent of drugmaker Chugai Pharmaceutical Co. that it doesn't already own and is instead focused on its $8.3 billion acquisition of InterMune Inc., according to a person familiar with the matter.

As it worked on the InterMune deal, announced Sunday, Roche was also considering a bid for Chugai, the person said, asking not to be identified because the talks were private. The Swiss company has decided against pursuing a deal with Chugai for now after the Japanese company's management signaled opposition to a bid, the person said.

Roche, which owned 62 percent of Chugai as of June 30, was in talks to acquire the rest of the shares for about $10 billion, people familiar with the matter said on Aug. 15. Chugai later said it is "in no way in the process of reviewing any plan to become a wholly owned subsidiary of Roche."