Northwest Airlines will start new daily nonstop service between Seattle and Beijing in March, a move that will bolster the Pacific Northwest's trade ties with China and give travelers more options for reaching key Asian cities.

Hainan Airlines, China's fourth-largest carrier, begins nonstop service from Seattle to Beijing on June 9.

"China is Washington state's Number 1 export market, with nearly limitless opportunities for growth," Gov. Christine Gregoire said at a news conference on May 8.

"Northwest Airlines' new flight will greatly expand our ability to increase trade, tourism, education and cultural exchange with China, bringing new jobs and economic development to our state," Gregoire said. "It also reinforces Seattle as the gateway to Asia and the Pacific."

The new service, departing Seattle at 4:55 p.m. and arriving in Beijing at 8:35 p.m. the next day, will use Airbus A330-200s equipped with 32 business-class seats and 211 economy-class seats.

Seattle already has nonstop service to three other Asian cities. United Airlines and Northwest fly to Tokyo. Other airlines fly to Seoul, South Korea, and Taipei, Taiwan.

"This just validates the fact that Seattle has become a major gateway to the Pacific," said Joel Chusid, North American general manager for Hainan Airlines, whose Seattle-Beijing service begins next month.

"Competition is competition, but we understand it. It just speaks to the vibrancy of the market."

While Hainan will have a nine-month head start on offering a direct flight to Beijing, it doesn't have Northwest's long-standing code-share agreements with Alaska Airlines and Horizon Air for connections throughout the U.S.

Last year, about 69,000 passengers flew between Seattle and China, not including passengers connecting through Seattle from other cities, according to Kazue Ishiwata, senior manager of air-service development at Seattle-Tacoma International Airport.

By 2009, that number is expected to nearly double.

More than 100,000 passengers are expected to connect to other cities through Seattle, bringing the total traffic to about 227,000 passengers.

"We are seeing the addition of the Seattle-Beijing service as very positive," said Mark Evans, Microsoft senior director, global procurement group, in a statement Northwest released on May 8.

"This will give our travelers the additional flexibility that they've been wanting and is very good news for the Seattle market," Evans said.

Northwest, which is being acquired by Delta Air Lines, already flies a daily nonstop between Seattle and Amsterdam and will start service from Seattle to London Heathrow on June 1.

The nation's fifth-largest carrier, Northwest is the major U.S. player in the Asian market, operating more than 200 nonstop flights between the United States and Asia each week.

Not all nonstops between Seattle and the Far East have lasted. Northwest started nonstop flights between Seattle and Hong Kong in 1994 but later suspended the service.

Seattle has been on a roll when it comes to picking up new nonstop international routes.

Sea-Tac gained four new international routes within the last year, bringing its number of nonstops to European destinations to six: Air France to Paris; British Airways to London; Lufthansa to Frankfurt, Germany; Northwest Airlines to Amsterdam and London; and SAS to Copenhagen, Denmark.

Other international service includes two airlines flying to Mexico, and four to Canada.