Dexter Corp. said yesterday that it will make a tender offer for the 48 percent of Rockville-based Life Technologies Inc. it does not own, after the maker of chemicals for biological research rejected Dexter's unsolicited $420 million bid.

The $37-a-share cash offer will be made directly to Life Technologies' shareholders. The price is 19 percent more than Life Technologies' closing share price before its original offer July 7, Dexter said.

Life Technologies, with 1997 sales of about $331 million, makes cell nutrients and other compounds used in biotechnology.

Dexter, based in Windsor Locks, Conn., generated 1997 sales of $1.15 billion from specialty chemicals used in the aerospace, food packaging, electronics and medical markets. The offer is part of Dexter's shift to focus on more profitable specialty chemicals such as those used in biotechnology.

"It's a fair price, and I doubt another bidder is going to step in," said Kevin Berg, an analyst at Oscar Gruss & Son Inc. who rates Life Technologies a "hold."

Shares of Life Technologies rose $1.625, to $36.625, yesterday. Dexter's shares fell 81.25 cents, to $28.875.

Pub Date: 10/29/98