The Federal Election Commission yesterday ordered Pennsylvania Gov. Milton J. Shapp to repay almost $300,000 in federal campaign funds and said it would continue to investigate possible criminal violations by Shapp's 1976 presidential fund-raising operations.

Among the targets of the inquiry, according to informed sources, is Eleanor Elias, a paid Shapp campaign fundraiser from Merion, Pa., who allegedly promised to reimburse a Georgia donor whose money was needed to help Shapp's campaign qualify for federal mathcing funds.

In another instance, according to sworn statements released yesterday by the commission. Elias allegedly asked an Alabama textile plant manager to supply her with letters from employees saying they had made $100 contributions to Shapp when they had not.

Under the law, a candidate must raise at least $5,000 in contributions of $250 or less in 20 states in order to receive in initial $100,000 from the Treasury and one dollar of federal money for every additional contribution of $250 or less collected thereafter.

Yesterday the FEC released its report on a three-month investigation into the fund-rais ing, for Shapp's bid for the Democratic nomination. The investigation found that irregular contributions in five of 20 states, including Georgia and Alabama, had permitted Shapp to claim on Jan. 21, 1976, he had qualified for federal matching funds.

Based on the findings, the commission yesterday ordered Shapp to repay $299,066.21 in federal matching funds his campaign received last year.

Shapp was unvailable for comment yesterday but scheduled a press conference for this morning in Harrisburg. A press aide said yesterday he was studying the FEC investigative report.

A Phildelphia lawyer, Gregory Harvey, who has represented the officers of Shapp's committee during the FRC inquiry, said yesterday he thought Shapp would appeal the ruling that the candidate, himself, was responsible for returning all the federal money given the campaign.

Under FEC yesterday also announced that fines ranging from $25 to $750 had been levied against 22 of 43 persons involved in the five-state investigation. Other fines are expected as a result of the FEC conciliation system with violators of the campaign fund law.

In the case of possible criminal violations, the FEC investigates - as it is doing with the SHapp fund raiser - but must turn its findings over to the Justice Department before an actual prosecution can take place.

Yesterday's investigative report showed the following activities in five states:

Alabama: The plant manager of Winfield Manufacturing Co. in Winfield, Ala., Hugh Walker, described in a sworn statement how he had been told by the firms's owner that Shapp needed "Some contributions made and some letters."

Walker paid $2,000 of his own money for a $500 contirbution in the name of his wife and himself and six $250 contirbutions sent by plant employees or their wives which Walker said he subsequently reimbursed.

Walker also testified he was called by Elias in January, 1976, about furnishing letters from employees who supposedly were making $100 contirbutions to Shapp's campaign.

According to Walker, Elias allegedly asked that he get the employees "to sign the letters but not to send any money and that she would take care of that."

Attempts to contact Eleanor Elias yesterday were unsuccessful. A woman who answered her phone said she was not avaialable.

Georgia: Stanley Siegel, secretary-treasurer of Norstran Industries, of Atlanta, and an old friend of the Elias family said he was contacted about contributing to Shapp in December, 1975.

Siegel said Elias told him, "Stanley, I hate to say this but you can get some friends who are not in a position to make a contribution and if you reimburse them I will reimburse you."

Siegel testified he did just that with contirbutions made in the name of his son, the general manager of his company and five $100 contirbutions for other employees.

Nevada: Five employees of various Las Vegas casinos testified they signed their names to ticket studs for a Shapp fundraiser but never gave the $100 for which they were subsequently recorded in Shapp fund records.

Texas: El Paso insurance man Charles Luciano, pressed by Elias, furnished $1,300 to a daughter and employees for their contrigutions to the Shapp campaign.

North Carolina: Gus Nicholas, a Pittsburgh resident with a summer home in North Carolina provided $50o for two $250 contirbutions by residents of that state.