A federal judge in Baltimore rejected Maryland's request for extra gasoline yesterday, saying that such an order would set off "chaos" in the nation's fuel distribution system.

At the same time, the Department of Energy deputy securetary, John F. O'Leary, met with repreentatives of Washington area governments and gasoline dealers associations to suggest that these officials use their powers to alleviate the long lines at service stations.

"I prompty told Mr. O'Leary that the State of Maryland already had initiated" many of the methods he was proposing, said Frederick L. Dewberry, the Maryland state representative.

"This is one of those meetings where we hear the same old thing," a Virginia representative told O'Leary.

The officials, nevertheless, agreed to return Jyly 16 for a second meeting time, O'Leary said, he might consider "Tinkering with the system" to alleviate the gas crunch here.

He did not elabrate on what that "tinkering" might include. But he did concede that only the metropolitan areas of Washington and New York and a few cities like New Orleans Continue to have excessively long lines.

At the day wore on, Virginia did take new action on its own to shorten the gasoline lines that have plaged the Washington suburbs -- and not most rural areas and the city of Richmond.

Virginia energy chief George Jones said he would send 3.5 million gallons of gasoline to Northern Virginia to retailers who could show hardship and an addition 1.5 million to gasoline station owners who agreed to extend their hours of operation.

Jones said he would send at last two members of his staff to Northern Virginia Monday to begin making emergency allocation on the spot from the state's so-called setaside gasoline allocations.

Meanwhile, long lines reappeared at the pumps yesterday as motorists with even-numbered license plates fueled up for the first time since Monday under the area's odd-even sales system.

Dealers in the area, however, predicted that gasoline should be somewhat easier to obtain over the weekend because the District and Maryland have already allocated extra gasoline to service stations that agreed to open on Sunday.

The American Automobile Association predicted that 62 percent of the area's stations will be open today.

New statistics released yesterday about actual consumption of gasoline in the Washington area showed what seemed inevitable -- motorists have been driving less.

The District reported that gasoline sales plunged nearly 8 percent or 1.5 million gallons in May, compared to the same month a year ago.

Virginia gasoline sales for May won't be available for another week, but state officials said its sales during April were down by about 1.5 million gallons from the year before.

Maryland, in testimony in its lawsuit in Baltimore, reported that gasoline sales in that state fell by 12 million gallons during May compared to last year.

Judge Herbert Murray, hearing Maryland's suit against the federal government's gasoline allocation system in federal court yesterday, said he recognized that the state had experienced "increased unemployment . . . increased violence and a waste of citizens' time" because of the shortage.

"But the court is not convinced this is the result of failure to act on the part of the Department of Energy," he said.

At the end of a two-day trial, Murray ruled that granting Maryland's request for extra gasoline could set off a rash of similar lawsuits throughout the country and "as many different allocations systems aes there are lawsuits filed.

"That would bring about chaos and would be disastrous to an extent far greater than the inconvenience we have experienced here at the gas lines," Maryland ruled.

The Maryland lawsuit charged that the federal allocation program -- in effect since May 1 when the gasoline shortage spread across the country was "irrational" and failed to provide for equal gasoline distribution among all regions and states.

The trial in federal court had become a war of statistics, with Maryland contending that it had received 25 million fewer gallons of gasoline last month than in June 1978. The state used secret oil company information supplied to the Energy Department to arrive at that figure.

Today, however, an Energy Department official, using data from the some sources, testified that Maryland actually got about 20 million fewer gallons last month than the previous June. The official, Doris Dewton, said the discrepancy occurred because the figures are based, in part, on projections by the oil industries that continually change. The department, she said, would not have reliable June data until August.

Murray, in his ruling, noted that the figures provided by both sides in the case "are highly speculative at best."

He said the outstanding fact from the plethora of conflicting figures "is that the gas shortage is a national phenomenon. The court believes Maryland probably is worse off than a number of states, but undoubtedly better off than a number of others."

During the trial, Maryland Attorney General Stephen Sachs presented evidence showing that the state's June allocation was proportionately lower than all but seven other states and the district of Columbia.

Attorney David Anderson, representing the Energy Department, argued that a year ago in May, Maryland received a greater share of gosoline than the national average. If Maryland received a greater share of gasoline than the national average. If Maryland's suggested allocation scheme had been in effect then, the state would have had to give up about six million gallons of gasoline, Anderson told the court.

Anderson conceded that the allocation system allows variations among the share of gasoline each state gets, but argued that "the variations of 3 and 4 precent are equitable."

Sachs said the federal allocations program was unfair for two major reasons.

He argued that the program fails in part because it does not take into account that every state is dependent on different gasoline suppliers, all of whom have established different nationwide allocation plans.

A second flow in the system, according to Maryland's lawsuit, is a special adjustment program that has been set up. It allows additional gasoline allocations to service stations that can show more than a 10 percent growth in gasoline purchases between October 1978 and February 1979. But it was during the same months that gasoline use decreased in states like Maryland because of an extraordinarily severe winter.

Maryland argued that because of these problems, the court should declare the entire allocation program illegal.

Murray, however. did not rule on that aspect of the case, and Maryland could still seek a trial on that issue.

Independent of the lawsuit, one tool recommended by the Department of Energy for alleviating lines is the switching of gasoline supplies from areas of surplus within a state to areas of shortage in a recent press release, the DOE spotlighted the regulation permitting oil companies to move up to 5 percent of the gasoline within a state from a surplus area to a shortage area.State officials trigger the movement by certifying an area as hard-hit.

But an O'Leary aide conceded yesterday that the switch wouldn't help a state like Maryland, where 80 percent of the population lives in a metropolitan area. And it wouldn't help the District, because it is entirely urban, the aide said.

"Virginia could utilize this step in a meaningful way . . . but I think that is one of the last things they will do because it has political problems," the aide said.

Telephone Help

Following are telephone numbers of agencies providing information to deal with gasoline emergencies:

Prince George's County "hot line": 779-1151. An official said it would be staffed around the clock.

Bowie area gasoline hotline: 262-6262. It is scheduled to begin operation at 5 p.m. today. It will featute a recorded message listing names, locations and hours of gasoline stations.

Frederick County motel/gas hotline: (30) 663-8687 or 662-2126.A spokeman said it is staffed 24 hours a day.

Anne Arundel County "hot Line." (301) 263-2681. An official said it would be staffed from 6 a.m. to 9 p.m. daily.

American Automobile Association: 222-5000. Officials said AAA members may obtain small quantities of gas or be towed to a nearby station if they are stranded.

Flag System

Washington area service stations have been asked to display special flags, noting the availability of gasoline.

A green flag means leaded and unleaded gasoline are available.

A yellow flag means only leaded gasoline can be purchased.

A red flag means a station's pumps are closed.

Gasoline station owners in the District of Columbia can pick up flags at the Munsey Building, 1329 E St. NW, Room 1258.

Contributing to this story was Washington Post staff writer Glenn Frankel. CAPTION: Graph, Daily Gasoline Guide, The Washington Post