United Airlines Inc., the third largest U.S. carrier, filed a trademark infringement suit against Bangladesh-based United Airways Ltd., claiming that its name will confuse customers of the American company.

United Airways plans to expand its air service from Bangladesh and India to markets including the United Kingdom, where United Airlines does business, according to the suit filed Nov. 2 in U.S. District Court in Brooklyn, New York.

United Airlines, which has more than 3,300 flights a day, said United Airways' English-language Web site encourages customers to book travel at an office in the Astoria section of New York City, according to the complaint. United Airlines told the Bangladesh carrier in 2007 to stop using its name and found out just this year about the sales office in New York, the complaint stated.

Efforts to obtain comment from United Airways in Bangladesh after regular business hours were unsuccessful. A representative at Jumbo Travel, reported in the lawsuit to be the sales office for United Airways in Astoria, referred comment to a number in the U.K. and a call wasn't immediately returned.

Shares of United Airlines parent UAL Corp., based in Chicago, lost 5 cents to $6.59 at noon New York time in Nasdaq Stock Market composite trading. They fell 40 percent this year before today.

The case is United Airlines Inc. v. United Airways Ltd., 09-04743, U.S. District Court, Eastern District (Brooklyn).