The Maryland Department of Transportation has postponed indefinitely more than 60 highway projects in the state, including 16 in Montgomery and Prince George's counties, to compensate for a sharp drop in state revenues from the gasoline tax.

The postponed projects, all in the planning stages and previously included in the state's six-year construction program, include the controversial Intercounty Connector, state takeover of ownership of the Baltimore-Washington Parkway from the National Park Service, reconstruction of sections of the Beltway, Georgia Connecticut and Central avenues and work on more than half a dozen other roads in the two counties.

Public briefings are scheduled for Tuesday in Prince George's, at 10:15 a.m. in the County Council chambers in Upper Marlboro, and Dec. 13 in Montgomery, at 9 a.m. in the County Council offices in Rockville.

The 62 projects deleted from Maryland's six-year construction program are still included in the long-range, 20-year transportation plan and could be built if the state increases its gasoline tax or allocates other funds for transportation programs.

Another 90 highway projects have been dropped from the 20-year plan, in effect killing those projects, at least in this century.State highway planners said this week they do not have a separate list of the 90 projects or know which ones are in the Washington area. All were in early planning stages and little or no money had been spent on them, according to state highway officials.

The state had hoped to spend $1.1 billion on highway construction over the next six years, but projected returns from the gas tax -- the major source of income for all state transportation programs -- $380 million short of that. Gov. Harry Hughes said earlier this year he would urge the General Assembly to increase the 9-cents-a-gallon tax, last raised in 1972. The governor said this summer, however, that he had changed his mind.

The biggest and most expensive highway project being postponed is the Intercounty Connector, now the subject of a $1.5 million, three-year study. It originally was proposed as a 22-mile, six- or eight-lane freeway between Gaithersburg and Laurel and a 10-mile spur south of Rockville, which together could cost more than $325 million.

Even two years ago its construction was viewed as doubtful because of public opposition and insufficient federal and state funds. Other less expensive and less disruptive alternatives for improving cross-county travel, such as widening and improving present east-west roads, are be considered. A consultant is expected to recommend seven preferred alternatives this month.