The long-planned Tysons II regional shopping center has been scrapped and its land sold to a Boston-based developer who will build a cluster of office buildings on the prized site in the middle of what has been called the downtown of Fairfax County.

Boston Properties bought the 117-acre parcel for $25 million from Washington developers Theodore N. Lerner and H. Max Ammerman, who had planned building a twin to their present Tysons Corner shopping center there. The complex would have been one of the largest suburban retail complexes in the world. But that was before the economy turned sour.

Boston Properties, the purchaser, is a two-man partnership headed by Mortimer Zuckerman, who recently attracted attention when he bought the prestigious but ailing Atlantic magazine, a cultural institution in Boston for almost 125 years.

Boston Properties plans to build up to 5 million square feet of office space at the Fairfax site, a project it can undertake without zoning changes -- is certain to have a number of significant repercussions in the Tysons area, which planners say is destined to become the center of the most populous locality in the metropolitan area by the end of the decade.

The main impact is likely to be traffic. An office complex of 5 million square feet would generate up to 15,000 cars, which would have to squeeze onto roads in the Tysons area that already are overburdened with more than 50,000 vehicles daily.

Another shopping center would develop even more traffic, but county planners said the impact would not be as harmful because the traffic would be spread throughout the day.

Lilla D. Richards, a leader of the McLean Citizens Association, which supported the Tysons II shopping center, called the new plan "the worst possible solution. We have been trying to avoid another Rosslyn, and that's what we're going to get."

One of the chief beneficiaries of the decision not to build Tysons II is likely to be the new regional shopping center called Fair Oaks, being built by the Taubman Co. of Detroit at the intersection of I-66 and Rte. 50 west of Fairfax City. Fair Oaks, which has six major department stores -- Woodward & Lothrop, Hecht's, Sears Roebuck, J.C. Penney's, Lord & Taylor and Garfinckel's -- is scheduled to open July 29.

The county wants to build a new governmental complex -- and perhaps a major cultural center -- on 150 acres nearby. The surrounding 4,000 acres, most of them undeveloped, are being mentioned as the possible site of a second major commercial center.

Development prospects for that area have been predicated on the assumption that Tysons would not gain much more office development than it currently has, more than 7 million square feet.

Boston Properties' plans for up to 5 million square feet of space at Tysons could slow down office development prospects in the I-66/Rte. 50 area. "The market is finite," said David A. Edwards, executive director of the Fairfax Economic Development Authority. "Presumably you would lesson marketing prospects somewhere else." a

Boston Properties signed a sales contract for the Tysons II site over the weekend, and president Edward H. Linde said settlement -- when ownership actually passes -- is scheduled for next March. "We plan a development at Tysons that will be attractive to leading businesses and corporations," said Linde. "We pride ourselves on the ability to construct buildings that are outstanding in quality and design. That's been our whole approach."

The firm, which has built 4.5 million square feet of offices in the Boston, Los Angeles, San Francisco and Philadelphia areas, entered the Washington area last December. It then announced it would build Capital Gallery, a $40 million, 600,000-square-foot office complex at Maryland Avenue and Sixth and Seventh streets in Southwest Washington.

Tysons Corner has a reputation not only for poor planning but poor architecture -- and Linde says that repuatation "is well deserved." He said that Boston Properties had engaged outstanding architects for its projects -- among them Victor Gruen Assoicates for Capital Gallery in Southwest.

As for the transportation mess at Tysons, Linde said, "we will do whatever roadwork is appropriate to make sure traffic works . . . I ask them [the critics of more office development at Tysons] to defer judgement until we present our plans."

Tysons' transportation problems will be alleviated when the Dulles Airport Access Road is extended to a new section of I 66 under construction inside the Capital Beltway. The extension would permit through traffic to bypass Tysons.

When Tysons II was expected to be a shopping center, the developers agreed to build a major interchange at Rte. 123 and International Drive. It is not clear whether Boston Properties will carry out that agreement. CAPTION: Picture, Theodore N. Lerner . . . $25 million sale, 1969 Photo; Map, no caption, By Dave Cook -- The Washington Post