The Federal Election Commission, forced by budget cuts to reduce sharply the amount of information available to the general public, has renegotiated a contract with a private computer firm so basic information services will be offered more quickly and inexpensively.

The savings would not result in restoration of the major service sacrificed to save money: computerization of individual donors, a process that allowed identification of major bankrollers of campaigns and political parties.

Instead, the revised contract with Digital Equipment Corp. will quintuple the speed at which information on campaign contributions and expenditures is received and printed for those making inquiries at the FEC.

In addition, for those who have bought the right to hook computers into the FEC's system, the hourly cost will decrease from $50 to $22, according to agency spokesmen.

"This is a good contact, a really good contact," spokesman Fred Eiland said. "We are going to get a lot more services from the vendor at much less money."

Along with faster services and lower costs, the new contract significantly increases the amount of computer memory available to the agency. As a result, it could put back into the computer system data from the 1982 election and earlier. At present, this information is available only by cumbersome examination of microfilm.

The net monthly cost to the FEC would be about $42,750 under the new contract, compared to $50,000 at present.

Maintaining computerized records of individual donors is separate from the computer contract because the keyboarding of individual donors had been done by FEC staff members, not the private corporation providing contractual services.

Eiland said that the FEC requested funds to add new keypunchers but that Congress "laughed at us."

Fred Wertheimer, president of Common Cause, the leading organization advocating public disclosure, noted that the FEC must decide this month whether it will continue to provide another basic disclosure service: keypunching of data from political action committees (PACs).

The FEC's five keypunchers have been able to put the material into the computer in timely fashion, he said, and the work is expected to continue at least through the November elections.

Along with saving money, the new computer contract allows the FEC to introduce new software programs that would allow various types of searches through campaign data, according to Eiland.

While no specific program have been devised, he said, private firms have tried to develop techniques to permit searches of the entire data system so complex patterns of expenditures and contributions can be traced.