Delta Increases Pan Am Offer to $310 Million : Aviation: The bid, which matches the one made earlier by TWA, is favored by the bankrupt airline.

The bidding war over Pan American World Airways’ lucrative European routes and Northeast shuttle intensified Sunday as Delta Air Lines increased its offer to $310 million.

Atlanta-based Delta, which earlier bid $260 million, said additional assets have been added to the deal. Pan Am, which is in bankruptcy proceedings, said it favors the Delta bid over a competing offer from Trans World Airlines, which also has said it would pay $310 million for key Pan Am assets.

Pan Am spokesman Jeff Kriendler said the airline will ask for an expedited bankruptcy court hearing on Delta’s bid. “We’ve been working with Delta on the details,” Kriendler said.

Delta would employ 6,000 of Pan Am’s 22,000 workers and would honor Pan Am tickets on the routes affected by the deal through Feb. 1, 1992, under terms of its offer. Delta has also agreed to provide $60 million in financing to New York-based Pan Am.

The additional Pan Am assets include spare engines and parts, as well as leases on 21 Airbus Industrie planes and 24 Boeing 727s, according to a Delta spokesman. Delta said it might also help Pan Am reestablish itself as a smaller carrier serving Latin American and Caribbean routes.

“We have negotiated a definitive deal with Pan Am management,” Delta spokesman Neil A. Monroe said. “We definitely feel that we’ve got the stronger proposal.”

UAL Corp., parent of United Airlines, has also bid for Pan Am’s Latin American routes, Pan Am’s only profitable division for the past two years. The two sides are said to be close to an agreement on the $235-million offer. Delta and United had discussed a joint bid for the majority of Pan Am assets before talks broke down last week.

A bankruptcy judge will ultimately decide how Pan Am’s assets are divided.

TWA had no comment Sunday on Delta’s counteroffer. In its bid last week, backed with $250 million in financing from American Airlines, TWA offered to pay $280 million for Pan Am’s European routes, the Northeast shuttle and other assets and to assume $30 million in ticket liabilities.

TWA said it would also invest $140 million in a reorganized Pan Am flying primarily in Latin America.

Analysts expect Delta to prevail because Pan Am, which must quickly sell off its assets, is pushing to accept Delta’s proposal. Analysts have also noted that TWA Chairman Carl C. Icahn has said that his airline might be forced to seek bankruptcy protection because of significant losses and other problems.

Pan Am filed for bankruptcy protection in January after racking up hundreds of millions of dollars in losses over a decade-long decline. It has already sold off valuable Pacific routes. In the first quarter of this year, the carrier’s losses totaled $249.2 million.

Delta first offered to buy Pan Am’s New York-to-Europe operations, its Miami and Detroit routes to London and the Northeast shuttle on July 11.

A Delta spokesman said the carrier will file updated legal papers with the bankruptcy court in New York today on Monday.