A a four-acre site in Southwest Washington, currently valued at $5.5 million, is being considered for development of a $40 complex that would include hotel, office and retail space.

Now the site of a gas station and a District Grocery Stores warehouse, the property bounded by 4th, 6th and G streets SW near the B&O tracks along Virginia Avenue is expected to be leased to a local development group on a 99-year lease by the Redevelopment Land Agency, which plans to acquire the tract for about $5.5 million.

Public hearings and approvals will be required before the planned complex can be started next year. The principal planner of the project is Herbert L. Tyson, a vice president of John F. Donohoe and Sons, Inc., and a property management specialist. He said the project will be undertaken by Donohoe Construction Co. and its investment affiliate along with three members of the Franks S. Phillips Co. - Leland H. Phillips, Paul C. Nasetta and James Earnest.

Tyson said the hotel complex may include at least 500 rooms and more than 700,000 square feet of office space, far more than average for Washington hotels and office buildings.

Two architectural firms, Mills & Petticord-HQK and Navy, Marshall & Gordon are drawing up plans for submission in four months.

While negotiations for operation of the planned hotel are now tentative, Tyson indicated it is possible that the Howard Johnson or Holiday Inn chain may be involved. The Donohoe firm currently is building the Georgetown Holiday Inn at 2101 Wisconsin Ave. NW.

Completion of the total project, which would be located near the NASA and HEW buildings, is not considered likely until some time in 1980 or 1981.