The Civil Aeronautics Board yesterday formally proposed to increase the public's participation in its proceedings by picking up the tab for the costs of such efforts.

Under the proposal, which will soon be published in the Federal Register to solicit public comments, reimbursement for the costs of participation would be provided to applicants who could be expected to make a "substantial contribution" to a board proceeding but who could not afford to participate without the board's financila help.

The compensation program is designed to bring to the board's decision making different positions that otherwise might be overlooked in proceedings that are generally heavily dominated by lawyers representing the interests of the regulated companies.

A Senate study issued last year found that 11 large airlines paid almost $3 million in 1976 to outside lawyers to represent them before the board - one carrier spent $650,000 - not counting the carrier's own personnel and lawyers who might have been involved.

In contrast, the Aviation Consumer Action Project the only "public interest" group that participates significantly in board proceedings, had a total budget of $40,000 that year, spending half of it on board motters.

The board's proposal was in fact a response to a petition by ACAP and the Institute for Public Interest Representation.

The vote on proposing the new program was 4 to 1 with Richard J. O'Melia the lone dissenter. He said he wasn't voting against the program but said he didn't think "legally we can do what we're doing."

He made reference to a case in which an appeals court found Federal Power Act did not authorize the Federal Power Commission to compensate participants without explicit statutory authority. The majority of the board members however, were swayed by the staff that the court decision had not addressed the Federal Aviation Act and does not preclude a CAB compensation program. In addition, it was suggested that the board has implied statutory authority for the program.

Several agencies, including the Federal Trade Commission, have explicit statutory authority for compensation programs; several others have instituted programs on their own. There are also bills pending in the Senate and House that would provide agencies with explicit statutory authority for such programs.