Anticipating sharp budget cuts from Congress this year, the Federal Trade Commission agreed yesterday to close four of its 10 regional offices--those in Boston, Denver, Seattle and Los Angeles--by July 15.

After a 90-minute private meeting, the four FTC commissioners agreed to FTC Chairman James C. Miller III's plan to offer the 82 full-time employes who now work in these offices the opportunity to transfer to Washington or get severance pay.

The decision came despite strong objections from several congressional members that the FTC should hold off closing the regional offices until it is clear that this is what Congress wants. Last year, members of Congress refused to allow the FTC to cut its budget by closing the regional offices, and many of them consider it likely that Congress will made the same decision this year.

"This decision, unless reversed, begins a process of dismantlement that will be painful, costly and, in all likelihood, unnecessary," complained FTC Commissioner Michael Pertschuk in a statement after the meeting.

However, Commissioner Patricia P. Bailey, who has had reservations about closing the offices ever since it was first proposed last winter, faulted the commission for not moving sooner to let employes know about their fate.

With the administration hoping to cut the FTC's budget from $68.7 million in the current fiscal year to $60.8 million in fiscal 1983, Miller argued that the commission had to close four regional offices this year while the commission had the money to pay for relocation and severance--which is expected to cost between $600,000 and $800,000.

Closing the doors of the four regional offices is expected to save between $1 million and $5 million, depending on how many employes decide to leave the agency instead of moving to Washington.

Should most of the 82 full-time workers decide to move here, there may have to be further personnel reductions next year, FTC officials indicated yesterday.

Cases now being handled by the regional offices will be transferred to the Washington office.

In addition to objecting to the decision to close the officies, Pertschuk and Rep. Benjamin Rosenthal (D-N.Y.), the chairman of the House subcommittee on commerce, consumer and monetary affairs, also objected to the decision being made in a closed-door session instead of in a public meeting.

Miller and two other commissioners voted to close the meeting to the public because it could involve discussion of some pending nonpublic litigation being conducted by the field offices. However, officials who attended the meeting said that very few cases were mentioned.