A 600-room, twin-towered Holiday Inn has been proposed for the 83-acre Shell Oil Metro East commercial and industrial site, Robert Manzi, the attorney for the developer, said this week.

Ralph Deckelbaum, owner of the Alexandria Old Town Holiday Inn and Bethesda Holiday Inn, has received a franchise to build a "luxurious mini-vacation" hotel, which would include several restaurants, a health spa, swimming pools and a private club, to serve the New Carrollton development.

Manzi disclosed the proposal as he spoke before the Prince George's County Council in support of a bill that would allow hotel construction under special circumstances in certain industrial areas.

The Holiday Inn would become the recreation center for the Metro East development, said Manzi, to serve "not only families and businesses, but people interested in mini-vacations as well."

Plans are already under way for the construction of an eight-story People's Security Bank building; two low-rise buildings for Rouse and Associates, a real estate development firm; a mid-rise building to house the Retail Store Employes Union Local 400, AFL-CIO, and a five- to eight-story building for real estate broker James W. Rogers.

Shell Oil Co. paid $3.8 million in 1977 for the Metro East site, which is in the center of a triangle formed by I-495, Rte. 50 and the Penn Central Railroad line and within walking distance from the station that will serve both the Amtrak Metroliner and the soon-to-open New Carrolton subway line. As the land developer, Shell will grade the land and build roads before selling the property to other developers.

Manzi said the proposed hotel "would bring the type of quality the county is always talking about. If you pass this bill, we will apply for the special exception (to build the hotel) the next day. This is a chance to really do something if we are going to compete with Crystal City and the I-270 corridor."

Manzi said that if the council approves the legislation and Deckelbaum's resulting special exception request, the hotel development could begin "by the end of next year's building season."

The council is scheduled to vote on the zoning bill Tuesday.