A plan that would require the developer of an Alexandria office complex to pay about $75,000 to establish a shuttle bus service -- the first proposal submitted under the city's new traffic management ordinance -- won unanimous approval last night from the city's Planning Commission.

The commission also approved a 40,000-square-foot addition to Alexandria Hospital, apparently ending a long dispute between the hospital and its neighbors. Both sides worked out a compromise before going to the commission.

The office complex and the hospital expansion must be approved by the City Council before they can be built.

The $25 million, 277,000-square-foot office complex would be built on Eisenhower Avenue by Radnor/Alexandria Corp., whose owners include Rockville developer Robert E. Buchanan and the Sun Oil Co.

Peggy Dubynin, the project manager, said she hopes that construction can begin late next year.

To comply with the city's traffic management ordinance, adopted this year, the partnership must reduce the amount of new rush-hour automobile traffic that the project would generate by at least 10 percent. The ordinance requires that tenants be encouraged to use car pools and mass transit.

The Radnor/Alexandria plan, worked out by the developer and city officials, requires that the corporation pay the city about $75,000 when the office complex opens. The money will be used to provide shuttle bus service between the complex and Metrorail.

The developer has also promised to pay about $25,000 a year to provide cut-rate transit fares for building tenants. And although the complex would include an 1,100-car garage, at least $3 a day will be charged for all spaces except those reserved for car pools.

Planning Commissioner James E. Hoben called the city's transportation management ordinance "a bellwether action among cities in this country," and said the Radnor/Alexandria plan was an excellent example of a developer and a locality cooperating to reduce traffic. Buchanan said that the plan represents an attempt to balance development needs and community needs.

The hospital expansion plan includes the addition of a new parking lot and surgical center. However, it does not include any commercial space for doctors' offices, an idea that neighbors opposed.

Jack Sullivan, president of the Seminary Hill Association, a group of neighbors that initially fought the plan, said the compromise "represents the first time in my memory that neighbors have the right to feel they have an understanding with the hospital. We're very pleased."

A. George Cook, president of the hospital's parent corporation, said he was "ecstatic" and that "the beauty of this is that we can go forward together."