The Civil Aeronautics Board yesterday recommended to President Carter that he approve Laker Airways' proposal to offer low-fare "Skytrain" air service between New York and London.

If the President goes along - and there is every indication that he will - travelers would be able to fly to London for $135 and back for about $101 on the no-frills, no-reservations flights that Freddie Laker has been proposing for almost six years.

During the peak travel season, Laker plans to use DC-10 that will seat 345 persons. One-class service on which food and alcoholic drinks would be at extra cost, would be offered.

The lowest fare currently available from the scheduled airlines across the Atlantic and back is $440, if the passenger is willing and able to reserve and pay for the ticket 45 days in advance and stay between 22 and 45 days. The regular coach fare between New York and London is $774 round-trip.

Under Laker's proposal and conditions in the license it has been granted by the United Kingdom, the "Skytrain" service would be limited to a certain number of flights - 11 a week in each direction during the peak summer season and one a day during the rest of the year on each of which Laker would only be allowed to carry 189 passengers. Although the flights would be scheduled travelers could not buy tickets more than six hours in advance of the flight.

The CAB recommended that Laker's innovative proposal be limited to a one-year experimental period to start 60 days after it flies its formal fare proposal with the CAB. This would give U.S. carriers time to develop similar competitive programs if they want to.

Yesterday, both Pan American World Airways and Trans World Airlines said they would match Laker's fares if the plan goes forward.

The CAB's recommendation to the President laid down several conditions for approval which are not generally part of foreign air carrier's permits:

Laker cannot institute service to John F. Kennedy International Airport in New York until it satisfies the board or the Port Authority that its plans for handling passengers will not create "a disruption" of airport operations, other carriers' operations or the activities of passengers and others at the airport. Laker has said it may fly out of Newark International Airport if Kennedy is not suitable.

Laker must get from each "Skytrain" traveler a written statement stating whether he or she has a confirmed reservation on another airline and, if so, which one. Then Laker has to notify that airline that the passenger is flying on Laker.

Laker must compile and keep for three months the names of passengers on each of its flight and turn them over within 48 hours to any other air carrier who asks for them.

Laker must file detailed monthly reports with the board on its operations.

The board's decision contains a proviso that Laker service be suspended if the United Kingdom restricts the operations of any U.S. carrier the U.S. Government designates to provide similar low-fare service competitive with Laker's.

Robert M. Beckman, Laker's Washington attorney, said he and Laker couldn't quibble with the provisions, even if they are unusual, because they're so "joyous" they got the go-ahead.

"What they're trying to do is cater to all the objections that have been raised, and we worked out means to solve them all a long time ago," Beckman said.

Under the law, the President is responsible for reviewing board decisions involving foreign rates or routes, and may accept, reject or modify board orders. In an April letter, Carter told the board that encouragement of price competition among carriers was "an important element" of his foreign air policy.