In an effort to shorten the state's growing gasoline lines and eliminate the practice of "topping off" gas tanks, Gov. Harry Hughes issued an executive order today setting minimum purchase requirements at all Maryland service stations.

Effective immediately, compact car drivers must purchase at least (KEY OFF) worth of gasoline when they arrive at the pumps, and drivers of larger cars must buy at least $7 worth.

Hughes also announced plans to alleviate gas shortages in the Washington suburbs and the Baltimore area by channeling as much as one million gallons of the state's reserves to those areas starting next week.

As Hughes was announcing his order today, officials in Virginia and the District also were discussing the possible remedies for the growing gas lines, although in less specific terms.

In Virginia, Gov. John Dalton today ordered state energy officials to work with service station operators in planning to stagger opening hours so all stations will not be closed at the same time of day.

Dalton said he is not yet ready to put a similar minimum purchases requirement into effect in Virginia. "I am hopeful voluntary conservation will delay this government action [in Virginia]," Dalton said.

A Dalton aide said the state already has been shipping some emergency "setaside" gasoline supplies to stations in northern Virginia.

District of Columbia Mayor Marion Barry has a "new plan" for dealing with the gasoline shortage and will announce it today, an aide said. The mayor was in West Virginia attending a bankers' convention today.

On Capitol Hill, Maryland and Virginia politicians were beseiged with telephone calls from irate and gas-hungry constituents. The politicians in turn called pressconferences and sent telegrams to state and federal officials demandingthat some action be taken.

At his press conference yesterday, MarylandGov. Hughes described his minimum purchase requirement and redistribution plan as strong initial measures that could have a "significant impact" in reducing long gas lines and panic buying.

"We're doing everything we can to reduce the problem of gas shortages," he said. "Obviously there is a limit to what we can do as a state . . . the long term solution to the problem will be at the national and international level."

His action falls short of imposing odd-even rationing - a plan of serving customers on alternate days according to the final digit of their license plate numbers. Such a plan has been credited with easing California gas lines.

Local officials have prepared an odd-even plan for the Washington area, but the final, simultaneous approval of the Maryland and Virginia governors and the District mayor would be needed to implement it.

Violators of the minimem purchase requirements will face fines of up to$100, Hughes said. The requirement will be enforced by station owners who are expected to call police if a driver tries to top off his tank.

The executive order includes three additional restrictions:

Individual sales of gasoline in cans must be limited to two gallons.

Home delivery of bulk gasoline to the general panic.

Private residential storage tanks is prohibited.

Future construction of such tanks on residential property is prohibited.

The Maryland minimum purchase requirement is $7 for cars and other vechiles of 6 cylinders or more and$5 for smaller cars and vehicles. Mopeds and motorcycles are exempt.

Hughes promised to take several further steps to ease the gas crunch, including a request to the federal Department of Energy and oil companies to increase their monthly allocation of gasoline to service stations in Maryland.

Service station operators who have been closing their pumps after a few hours of business each day will be asked to adopt a schedule of staggered hours to assure the supply of gasoline throughout the day, Hughes said.

Hughes' long-awaited plan was developed in recent days as the gasoline shortage worsened in Maryland. The governor has been criticized for failing to respond to the crisis earlier by increasing the amount the state sets aside for emergencies.

After working out final details of the plan with his energy task force, he presented a draft copy last night at a three-hour meeting in the governor's office with representatives of oil companies, station operators and the Maryland motorists association.

All three representatives responded to the plan with guarded optimism today.

"He's giving the motorists who are pretty beleaguered some hope,"said William Zorzi, a spokesman for the Automobile Club of Maryland. "It's a little tiny light at the end of the tunnel. Yesterday, we had nothing at all."

Telephones in Hughes' offices have barely stopped ringing for the last two days as people called in about the gasolineshortage. State house officials finally had to have a special phone line installed to handle the calls, and two summer interns were assigned to take them.

On Capitol Hill, Rep. Michael D. Barnes (D-Md.) held a press conference on the lawn of the Capitol and urged the public and news media to "relax a little bit" and not contribute [Text ommited from source](KEYWORD) CAPTION: Picture, Hughes announces rules requiring minimum gas sales.