The U.S. Department of Transportation is considering applications from four commercial U.S. air carriers, who are vying with each other to offer the next direct flight from the United States to China.

The four U.S. airlines competing to offer direct flights to China are American, Continental, Northwest and United. Monday was the deadline for the companies to turn in the economic data to support their bids.

American Airlines hopes to fly non-stop from its hub in Dallas - Fort Worth to Beijing. American Airlines' senior vice president, Will Ris, said the flights would open a gateway to China from the southern United States.

"Currently, travelers can only fly non-stop to China from four U.S. points, San Francisco, Chicago, New York and Los Angeles," he said. "But for the millions of passengers who live in the central and south and southwestern part of the country, none of these cities are nearly as accessible as Dallas-Fort Worth."

He added that China has become a top trading partner for the state of Texas, second only to Mexico.

The American Airlines bid is facing tough competition from United Airlines, which wants to operate direct service from Washington to Beijing. United Vice President Mike Whitaker says there is currently no non-stop service between the U.S. and Chinese capitals.

"Twenty-eight other countries have non-stop service from their capitals to Beijing, including every major European and Asian country, from Paris or Tokyo, Moscow, even Tehran, you have non-stop service to Beijing," he said. "But there's no Washington-Beijing service."

He said Washington is the largest U.S. city that does not have non-stop service to China. He added that northern Virginia, right outside of Washington, is home to hundreds of high-tech firms, which has led to increased demand for business travel to China.

The other two bids are from Continental Airlines, which is proposing to link New York with Shanghai, and Northwest Airlines, which is prepared to fly from Detroit to Shanghai.

The Department of Transportation declined requests for an interview and said it does not want to make comments that might be interpreted as favoring any of the four U.S. companies.

The agency's decision is expected later this year or early next year. The flights would start in March.

Under an air services agreement the United States and China signed in 2004, U.S. carriers operate 133 weekly flights to China. By 2010, that number is expected to increase to 249 flights per week.