On Jan. 21, 1976, after a hectic, last-minute cross-country fund-raising effort, the committee supporting the Democratic presidential nomination campaign of Pennsylvania Gov. Milton Shapp filed an inaccurate and perhaps illegal request for federal matching funds with the Federal Election Commission, according to informed sources.

The FEC will meet today to make public its three-month staff investigation of irregularities in the Shapp campaign fund raising. It will also ask that all or a portion of the $299,062.21 in matching funds the Shapp campaign veentually received be returned to the Treasury.

The Shapp committee, in its January, 1976, letter, listed 20 states in which it said it had raised the required $5,000 in contributions of $250 or less. A candidate who met that requirement was automatically entitled to receive one dollar in federal funds for each dollar raised. He also was entitled to matching federal funds for every contribution of $250 raised thereafter.

The FEC investigation of the Shapp campaign has come up with irregularities in the original filing which would have disqualified the Pennsylvanian's campaign from qualifying for his initial federal funds.

Texas was one of the last of the 20 states where the Shapp committee claimed it rached the required $5,000 threshold level. Its January, 1976, letter said contributions from Texas totaled $5,007 in amounts of $250 or less.

According to a Texas source, however, the FEC investigation discovered one El Paso businessman had divided his own contribution of over $250 among severl of his employees. Thus, the excess money, which could not have been matched, was included for matching.

The businessman, according to informed sources, said he "made a mistake" and will be required to pay a fine. He made his contribution after attending a breakfast with Shapp in El Paso at the time of the 1976 Sun Bowl game.

Another Texas donor of $200, who helped Shapp just make the limit, was listed as Alfred Pereira of El Paso. On Feb. 26, 1976, just 24 days after Shapp's committee got its first $100,000 in matching funds, the $200 was refunded to Pereira, according to Shapp records filed with the FEC.

Pereira was not available for comment yesterday. FEC spokesman could not say whether it was proper for threshold contributions to be refunded.

In Harrisburg, Shapp's office released a statement saying the governor "has been aware for several months" of the FEC inquiry.

"Gov. Shapp noted that he and his campaign officers had done everything resonably possible to assure that his campaign was in complete compliance with the Federal Campaign Practices Act."

Shapp dropped out of the presidential race after running far behind in the Florida primary.

Although FEC officials would not comment on the results of their investigation, a review of the Shapp committee's FEC filing gave some hints at contributions that may be under investigation.

In two states, Colorado and California, where Shapp just met the $5,000 level in his initial filing, contributions of $250 were included from consultants who were on Shapp's committee payroll.

In two other $5,000 states, North Carolina and Alabama, the Shapp committee recorded groups of contributions from employees in one company.

In Alabama, for example, $250 contributions were shown to have been received from eight employees and their wives in a single manufacturing plant. The plant manager yesterday refused to take a call on his contribution. The wife of a sewing machine machanic, who along with her husband was listed as giving $250 as was her husband, hung up after being asked about her contribution.

In Nevada, the Shapp campaign reported raising exactly $5,000 at a single Nov. 9, 1975, event at the Las Vegas Country Club. Each of the donors listed gave $100, according to the Shapp report.

In North Carolina, according to the Shapp report, $1,000 worth of contributions were ruled ineligible for matching because the checks had no signatures on them.

Another $2,500 of the remaining $5,000 from that state came from 10 individuals in Ellerbe, N.C., associated with a single trucking company.

One of the listed Ellerbe donors said yesterday he had given the money because "we-re in the trucking business and Shapp had been good to truckers."

He said FEC investigators had interviewed him and his wife, who also gave $250, two months ago.

He complained that the FEC investigators had secretly taped the conversation and that "I should not have let them in here in the first place."