Thermo Fisher in $6 billion bid for Millipore: source

Millipore, which has a market capitalization of about $4 billion, makes filters and purifiers for laboratory water and other materials used in making biotechnology drugs. The company has hired Goldman Sachs Group as its financial adviser after receiving the bid, the source said.

The news, initially reported by Bloomberg, sent Millipore shares soaring as much as 36 percent on Monday to an all-time high, while Thermo shares were off about 5 percent. Bloomberg also reported that the deal could be done as early as next week, citing a person familiar with the situation.

A deal would be the first major transaction for Thermo's new Chief Executive Marc Casper, though not for the company as a whole.

Past transactions have included the acquisition of Fisher Scientific International by Thermo Electron, as it was previously called, to create the world's largest scientific instrument maker. Last month, Thermo agreed to acquire analytical instruments maker Ahura Scientific for $145 million.

Earlier this month, Millipore posted a better-than-expected quarterly profit, helped by strong demand from the company's biotechnology customers and higher levels of vaccine production.

Thermo spokeswoman Karen Kirkwood declined to comment on the report, calling it a rumor. Millipore did not immediately return calls seeking comment. Both companies are based in Massachusetts.

Millipore shares were up $15.12 or 21.2 percent at $86.46 in afternoon trade on the New York Stock Exchange after climbing as high as $97.58 earlier. Thermo Fisher shares were off $1.66 or 3.4 percent at $47.56 on the NYSE.

(Reporting by Jessica Hall; additional reporting by Bill Berkrot in New York; editing by Gerald E. McCormick)