A new nationwide wave of gasoline price increases announced by major oil companies yesterday will immediately add 3 cents a gallon to the price of gasoline at about a third of the service stations in the Washington area.

Some companies also boosted their price for home heating oil yesterday by 3 cents a gallon. The average cost of that oil is now about 94 cents a gallon here, up more than a penny and a half during the last two weeks, according to a Washington Post survey of 15 local heating oil distributors.

The average price of a gallon of gasoline in Washington and nationwide was about $1.05 a gallon last month, and a leading industry analyst predicted yesterday that the national average price will rise to $1.25 a gallon by the end of March.

"In view of the latest increases, the possibility of getting to that number [soon] increases," said Dan Lundberg, publisher of the respected gasoline marketing publication, the Lundberg Letter.

The 3-cent gasoline price increases were announced yesterday by Exxon, which controls about 24 percent of the Washington gasoline market, and by Texaco, which controls about 5 percent.

Chevron and Phillips also raised gasoline prices 3 cents a gallon yesterday, but neither has a significant share of the Washington market.

At the same time yesterday, Exxon and Phillips announced 3-cent increases in the price of their home heating oil. Texaco, Exxon, Gulf, Amoco and Chevron all had earlier raised their home heating oil prices between 3 and 6 cents a gallon since the middle of last month.

Shell, which controls about 6 percent of the gasoline market here, raised its prices 5 cents a gallon on gasoline and 6 cents on home heating oil Wednesday.

All these price increases should appear at the pump almost immediately since the U.S. Department of Energy, which controls gasoline prices, permits dealers to pass on wholesale costs directly to motorists. Home heating oil prices are not controlled.

In announcing the increases, the companies said they were caused by increases in world crude oil prices. The average crude oil price charged by members of the Organization of Petroleum Exporting Countries climbed from $22 to $26 per 42 gallon barrel in conjunction with the carterl's year-end meeting in Venezuela last month.

Anticipating that increase, the U.S. oil industry raised gasoline prices by between 3 and 6 cents a gallon and increased home heating oil prices by an average 3 cents a gallon in mid-December.

The companies also attributed yesterday's price rises to inflationary increases in their operating expenses.

While gasoline prices continue to skyrocket, the amount of gasoline released by the oil companies to consumers this month will be the smallest monthly gasoline supply in the United States since February 1975, according to the latest issue of the Lundberg Leter.

The publication raises the question of whether prices will rise high enough to keep demand down to this highly restricted supply level, and in a telephone interview yesterday, Lundberg said that he doesn't "think that the powe of price to curtain consumption is as great as has been imagined."

On the other hand, Lundberg said, indications from his network of surveyers all over the country are that people are finally getting serious about conservation in the wake of recent events in the Middle East.

Polls by The Washington Post and others in the recent months showed that the majority of Americans did not think that there was a real worldwide oil shortage or that the energy crisis was real.

"There has been a vast psychological turnaround," Lundberg said yesterday. "The majority of people no longer think the energy crisis is a fake . . . Consciousness of the crisis and the need to conserve will play a much greater role in curtailing consumption than mere price impact."