Mr. Ronchi, now the president and chief executive of Memorex International N.V., will soon head the proposed merger of Memorex and the Telex Corporation.

LEAD: The investor Asher B. Edelman said he had extended until Nov. 20 his $65-a-share offer for the outstanding shares of the Telex Corporation.

That could well be the case in the bid by Asher B. Edelman for the Telex Corporation.

Viking of Minneapolis (Division of the Telex Corporation)

Telex Communications (formerly Telex Corporation), an American manufacturer of hearing aids, audio equipment, and computer peripherals.

Mr. Edelman is also trying to take over the Telex Corporation, and industry analysts said they expected him to give up on Rexham.

Stephen J. Jatras has held the top position at the Telex Corporation through the recent good times for the company.

Telex Communications, originally Telex Corporation, was a Burnsville, Minnesota-based manufacturer of hearing aids and audio equipment.

The Telex Corporation agreed yesterday to be acquired by Memorex International N.V., a rival computer equipment maker, in a deal valued at about $900 million.

Asher B. Edelman, the New York financier, said yesterday that a group he heads would probably reduce the price later this week of an $880 million hostile offer for the Telex Corporation.