Dainippon Sumitomo Pharma Co. Ltd.'s (4506.TO) reported interest in buying Sepracor Inc. (SEPR) for about $2.7 billion could allow the Japanese company to prepare for the U.S. launch of its schizophrenia drug, Lurasidone, which it plans to file with the Food and Drug Administration in early 2010.

Shares of Sepracor were halted for pending news Wednesday afternoon in the U.S. after they surged 26% to $22.80 on the report in the Nikkei, a Japanese newspaper. With the gain, the company has a market capitalization of about $2.5 billion.

Sepracor officials weren't immediately available for comment. A U.S.-based spokesperson for Dainippon declined to comment, while officials in Japan weren't available.

Although Sepracor traded close to $30 early last year, Piper Jaffray analyst David Amsellem said that the company was unlikely to fetch much more than the Dainippon deal from another bidder, because the company is facing generic exposure in coming years and has a thin product pipeline.

Last week, Dainippon reported the success of its second late-stage trial of Lurasidone and confirmed it is on track to file for marketing approval. If it is approved, it will be the company's first drug in the U.S.

To make such a move, Dainippon is likely to need a sales force with experience in selling such drugs in the competitive U.S. market.

Sepracor could be a good fit for a company looking for that type of infrastructure, said RBC Capital analyst Adam Greene.

Sepracor, which had $1.3 billion in 2008 revenue, gets most of its sales from insomnia treatment Lunesta and the asthma treatment Xopenex, and filed for U.S. marketing approval of Stedesa, an epilepsy treatment, in June.

But both of those top sellers could lose U.S. patent protection in coming years. Lunesta's growth has already been hurt since the Sanofi-Aventis's (SNY) Ambien insomnia drug became available in cheaper generic versions.

"I think this is probably the best possible outcome for Sepracor shareholders," Amsellem said.

If confirmed, the deal would be another example of Japanese drug makers extending their reach into the U.S.

Last year, Takeda Pharmaceutical Co. Ltd. (4502.TO) acquired U.S. biotech firm Millennium Pharmaceuticals for $8.8 billion, while Eisai Co. Ltd. (4523.TO) bought MGI Pharma Inc. for $3.9 billion.

-By Thomas Gryta, Dow Jones Newswires; 212-416-2169; thomas.gryta@dowjones.com

(Shara Tibken contributed to this story.)