NWA Inc. board of directors Friday rejected as insufficient an unsolicited offer of $2.6 billion from oilman Marvin Davis, who said he will try again, and analysts agreed it was not enough for the parent company of Northwest Airlines.

"Our board has carefully considered Mr. Davis' proposal, as well as numerous other financial and strategic alternatives available to NWA," NWA Chairman Steve Rothmeier said. "It is clear that Mr. Davis' proposal does not fully reflect the value of NWA."But Davis said he is not deterred by the rejection.

"We hope this can still be a friendly acquisition," a spokesman for Davis said. "But Mr. Davis intends to proceed regardless."

An airline analyst said the $90 per share was too low. Northwest stock closed Friday down 50 cents to $88.75 on the New York Stock Exchange. Trading had closed when Northwest rejected the offer.

"I think Northwest stock will be headed higher," said Kurt Rivard of Dain Bosworth Inc., Minneapolis. "I think a hostile takeover by Marvin Davis is going to be difficult. Trying to take over an airline without the help of management would be very difficult."