The Alexandria Planning Commission recommended last night that plans for a massive 32-acre office and condominium development in the city's West End be rejected, citing concerns that it would create traffic problems.

By a unanimous vote, the commission urged that the proposal to erect nine high-rise buildings at Shirley Highway and Braddock Road be halted. The final decision will be made by the City Council, which is not bound by the commission's recommendation.

The project, which would include 1.8 million square feet of office space and 360 condominiums, was proposed by the owners of the site, the heirs of the late Paul T. Stone. But a lawyer for the owners, John Fagelson, said that even if the City Council approves the plan, the owners have not set a firm date for starting construction; he declined to give details of the plan.

Some business officials, citing an abundance of available office space, are predicting that the office vacancy rate in Northern Virginia will rise in coming months.

Under Alexandria ordinances, property owners have up to 18 months after the City Council approves a site plan to begin construction. If they have not broken ground by then, they must resubmit the project to the Planning Commission.

Although the project would be in an area that already has considerable high-rise development -- the site is next to the Southern Towers apartments -- representatives of several West End citizens groups said that additional traffic generated by such a large project could hopelessly jam local streets during rush hours.

"Many of us fear it is the development that will sink the West End," said Jack Sullivan, president of the Seminary Hill Civic Association. "It is inconceivable that we could handle thousands of additional cars on existing roadways."

But Bernard Fagelson, another lawyer for the site owners, said, "This land has been zoned for development for years. Our project is compatible with its surroundings. There it is."

One of the Planning Commission's key objections to the project was that the owners want to create more than 5,000 parking spaces; city planners have recommended that about 3,000 spaces be created. Planners said that limiting parking would encourage people who work at the site to use car pools and mass transit.

Fagelson pointed out that the owners have offered to spend more than $500,000 to buy four buses for the city transit system and to set aside parking spots for car pools. But commission members said the measures do not go far enough.

Fagelson said that if the City Council agrees with the Planning Commission recommendation, the property owners may challenge the decision in court.