A Virginia judge directed the Alexandria City Council yesterday to approve plans for a controversial four-building office complex along the George Washington Memorial Parkway at the north end of the city.

Circuit Court Judge Wiley R. Wright Jr. ruled that the city had no legal basis to withhold its approval of the 200,000-square-foot project, and must approve site plans for it at the Council's regular meeting Nov. 9. The developer, Wright said, could not be held accountable under Virginia law for traffic congestion caused beyond its boundaries.

City approval of the complex had been delayed for six months while the Council, the developers, citizen opponents and the National Park Service tried to resolve traffic problems the project is expected to cause along the parkway.

The project's developer, Potomac Investment Associates of Potomac, sued the city in August, accusing the Council of "willfully and wrongfully" failing to act. The court initially refused to intervene in the matter, but yesterday Wright ruled after a two-hour hearing.

"The court finds the site plan complies in every respect," he told lawyers for the city and developers. "The petitioners have proven to the court's satisfaction that they are entitled to approval of the site."

Project opponents, many of whom live in the neighboring Marina Towers Condominiums, vowed yesterday to continue their fight and several city officials said they are likely to appeal the issue.

"As far as I'm concerned, this can go all the way to the Supreme Court," said Councilman Donald C. Casey, a Democrat.

Opponents of the project said they were troubled by Wright's refusal to consider the impact that the project would have on rush-hour commuters. "If the effect on traffic is not to be a consideration for development, then we can just kiss the rest of Old Town goodbye," said Jean Caldwell.

The original plans for the project, to be built next to the parkway at Slaters Lane and East Abingdon Drive, were approved by the Planning Commission last spring. That decision was appealed to the City Council by residents and the National Park Service, who cited traffic and drainage problems. Since then, the developers have redrawn their plans, but the traffic issue remains. The developer has promised land and $45,000 to widen nearby parkway access roads. Last week the City Council, over the developer's protest, sent the amended project plans back to the planning commission.