Information compiled by the nation's lenders on whom they made home loans to last year will not be made available until next fall under new federal guidelines. For the past 14 years, the data had been released in the spring.

The projected seven-month delay in disclosing the information used by consumer activist groups to prove discrimination in lending practices has set off protests by those organizations.

The activists claim that the Federal Reserve Board, the regulator in charge of implementing a new version of the long-standing mortgage disclosure law, is trying to cover up for the banks that discriminate.

But the Fed defended its information-processing decisions, saying that the massive new data requirements of the revamped Home Mortgage Disclosure Act preclude any faster release of the information.

When lenders recount their 1990 mortgage and home improvement lending activity to their federal supervisors this spring they will provide far more detail than in the past as a result of the revised law.

They must now account for loan applicants as well as approved borrowers, bringing the likely number of reported transactions to between 5 million and 10 million, according to the Fed.

For each of those transactions, lenders must now also identify the race, gender and income of the borrower or applicant.

The agency's new marching orders, said Federal Reserve economist Glenn B. Canner, will generate "1.7 million pages of output. That is taller than the Washington Monument."

The information delay still remains unacceptable to Gale Cincotta, head of the Chicago-based National People's Action, a coalition of community groups. The delay, Cincotta said, allows lenders suspected of discriminating to "say that is old data and we're doing better now."

To underscore its point, members of Cincotta's organization have recently demonstrated at Federal Reserve branches and banks in 24 cities elsewhere in the country and, in Chicago, conducted a 40-person sit-in at the Federal Reserve Bank there.

Cincotta said she would prefer to see the disclosure data broken into two reporting systems. The banks, she suggested, could continue to release the same information on March 31 as they did before the new law, while the Federal Reserve could compile the new information and release it in November as it plans to now.

Until now, lenders have reported on their lending activity by breaking it down into census tracts. Community groups then took that data and overlaid it on a map showing census tracts by racial composition and income. Oftentimes, the results of that exercise "are devastating," Cincotta said.

Cincotta said her group has used such information to persuade lenders to reinvest $2 billion in mortgages and other loans in neglected neighborhoods.

The American Bankers Association is also concerned about the veracity of the new data, but for different reasons, said Paul Smith, senior federal administrative counsel for the group.

A statistician hired by the banking lobby to analyze the data has identified several variables other than discrimination that could explain a rejected loan application but are not covered by the new disclosures, he said.

In a recent letter to Cincotta, Griffith L. Garwood, director of consumer and community affairs for the Federal Reserve, acknowledged the "negative price of some delay" under the new timetable. That should be weighed, though, he contended later in the letter, against the "better picture of the fairness of the mortgage granting process" that the increased data should yield.

Cincotta, however, said she believes that picture is flawed because the 33 cross-tabulations the Federal Reserve plans to eventually release break out the race of borrowers and applicants only by metropolitan area and not by census tract for each lender. Lending "in the aggregate looks better for an institution than how it plays out by census tract," she said.

Cincotta rejected as too costly and too technologically sophisticated a suggestion by the Federal Reserve that groups like hers buy magnetic tapes of the raw data when it is released in October and then perform their own statistical studies.

Allen J. Fishbein, general counsel for the Center for Community Change, an organization that monitors lending practices, is critical of the Federal Reserve's failure to require more mortgage banking companies to comply with the new law.

Although the revised law was intended to pick up more lenders in that category, Fishbein said, the agency exempted those with assets of less than $10 million, thereby adding only three dozen of the country's estimated 7,000 mortgage companies to the reporting base. "A mortgage company could be nothing more than a desk and a phone," he said.