BANGOR – American Airlines announced Tuesday that it will terminate its regional jet service at Bangor in early November, citing financial reasons for the pullout.

American Eagle, the regional American Airlines affiliate, will discontinue its routes from Bangor International Airport to Boston’s Logan International Airport and La Guardia International Airport in New York City, beginning Nov. 5.

The departure means BIA will lose its third-largest carrier and 89 American Eagle employees, said Andrea Huguely, spokeswoman for American. The airline will close its station in the airport terminal, which employs 15 people, and its maintenance base that employs 74. American employees are being offered open positions within the company at other airports and would receive relocation packages, she said.

“It was completely a financial decision,” said Huguely. “Our operations at Bangor have been unprofitable for many years. This decision has nothing to do with job performance. It has nothing to do with the airport; they have been wonderful supporters. It is strictly financial.”

American Eagle moved into Bangor in 1999 when the company acquired BEX, or Business Express Airlines, Huguely said. The airline provides jet service to Boston from Bangor three times a day during the week and four times on the weekend. American Eagle also flies once a day to New York during the week and twice a day on weekends, she said. The company uses 37-seat regional jets on both routes.

American Eagle is one of five airlines that serve BIA, and at present the company holds approximately 20 percent of the Bangor market share, said BIA Director Rebecca Hupp. In 2000, American held 47 percent of the Bangor market.

The decision came as a surprise to BIA management, since American’s intent was to notify its employees first, said Hupp. BIA officials received confirmation of the pullout on Tuesday.

“There is certainly a demand within the Bangor market, and we hope to fill the void left by American Eagle,” Hupp said. “We are always actively searching to provide additional air service in Bangor.”

Despite American’s decision, BIA will continue to fly passengers to eight major hubs. Delta Air Lines will continue to fly from BIA to Boston, while US Airways also flies the La Guardia route.

The news on Tuesday cast a shadow on the airport’s announcement pegged for today, during which BIA is expected to name a new carrier.

“American pulling [out] is not related” to the new carrier coming in, Hupp said. “The airlines would serve different markets and have a different niche. Besides, American would not have been privy to our announcement [for] tomorrow.”

In a joint press release issued Tuesday evening, U.S. Sens. Olympia Snowe and Susan Collins expressed dismay at the loss of service and jobs.

Customers who use American Eagle to fly into or out of Bangor should not notice any changes until Nov. 5, Huguely said. The airline has begun calling customers who have booked tickets to or from BIA after Nov. 5, informing them of the change. These customers would be offered a full refund, a ticket to fly with American Airlines out of another city, or they could be booked with another carrier, Huguely said.

American Eagle customers who need to switch service as a result of the pullout may call 800-433-7300.