Millipore, which is under a $6 billion takeover offer from U.S. laboratory equipment maker Thermo Fisher
Scientific, said it hired Goldman Sachs as an advisor in evaluating "strategic alternatives." A source familiar with the situation told Reuters on Monday Thermo Fisher Scientific has offered to buy Millipore. Millipore said it not has set a definitive timetable for completion of its evaluation.

It has engaged Goldman Sachs as its financial advisor and Cravath, Swaine & Moore LLP as its legal advisor, it said in a statement.

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.