Tysons II, a proposed 107-acre office, shopping and hotel complex that would be one of the largest commercial projects in Northern Virginia, has won an important endorsement from Fairfax County officals.

The county planning commission voted 10 to 0 Thursday night to recommend rezoning the largest remaining undeveloped tract in the Tysons vicinity despite the fears of some area residents that new buildings there will generate more traffic in the already congested Tysons Corner area.

The commission's approval was a significant step for the $400 million Tysons II project, which has stirred controversy since it was first proposed more than a decade ago.

The vote, however, is only advisory to the Fairfax County Board of Supervisors which may accept, reject, or modify the proposal when it considers the issue on Oct. 15.

The commission acted after John T. (Til) Hazel Jr., attorney for the project's developers, H-L Land Improvement Venture, had promised the county $14 million for road improvements to handle the increased traffic.

"We think we have done enormous things to address transportation problems for Tysons," Hazel said.

Some area residents complained that Tysons II still could cause major problems because the developers' proposal did not do enough to improve roads around Tysons, an area some county officials call "downtown Fairfax."

Gloria A. Adams, the president of the McLean Citizens Association, called the projected traffic "tremendous" and urged further road concessions from developers.

The site for the Tysons II complex, north of Chain Bridge Road (Va. Rte. 123) and across the highway from the Tysons Corner shopping center west of the Capital Beltway, has been described in advertisements as "probably the most valuable property on the East Coast."

The development is a joint venture of Homart Development Co., a Chicago-based subsidiary of Sears, Roebuck and Co. and Tysons II Development Co., a Bethesda-based concern headed by Theodore N. Lerner, a Washington shopping mall magnate. He has developed malls at Tysons Corner, White Flint and Landover.

The developers plan to build two large hotels, a series of office towers and a three-story, galleria-style shopping mall to be anchored by major department stores, such as Saks Fifth Avenue and Macy's.

Citizens concerned with traffic congestion in the vicinity of the project have pressed the developers for two bridges across Chain Bridge Road to avoid backups at intersections.

The developers, arguing that two spans are unnecessary and impractical, have offered to pay half the cost of constructing one bridge over the road.

It would connect Old Westpark Drive on the Tysons II side of Rte. 123 to the existing shopping center side.

The planning commissioners also voted to recommend that the developers submit to the county all the architectural plans for the project.

Hazel called this concept unacceptable.