The deputy controller of the D.C. Department of Human Services has told the FBI that he believes then-Human Services Director David E. Rivers pressured him through his supervisor to give a favorable rating to an OAO Corp. bid for an agency contract, according to knowledgeable sources.

Employes from two other city agencies, in addition, have told the FBI that they were overruled by their superiors after raising objections to decisions favorable to a wholly owned subsidiary of the firm, sources said.

The employes have alleged that the city's Minority Business Opportunity Commission violated its own rules in allowing the subsidiary, OAO Services Inc., to participate in the city's minority contracting program and that the Department of Administrative Services improperly awarded OAO Services $496,000 in business without competitive bidding.

Alleged favoritism toward OAO Corp. and OAO Services, local firms that have received $11.3 million in contracts from the District government since 1984, is an element in a two-year investigation by federal authorities scrutinizing the actions of several contractors and city officials, according to sources.

The FBI is investigating whether OAO, in three D.C. contracts, received special treatment because it hired the accounting firm that employs Elijah B. Rogers, the former city administrator who maintains close ties to Mayor Marion Barry, sources said.

One top executive of OAO Services, Tina Scott, vice president for marketing, has been called to testify before a federal grand jury. No one has been charged.

Cecile D. Barker, chief executive officer of OAO Corp. and OAO Services, said through his attorney yesterday that the companies "have done nothing improper" in obtaining D.C. contracts.

Rogers has said through his attorney that he has never tried to influence city officials in the award of contracts to OAO or any other firm.

John F. Mercer, an attorney for Rivers, said he was not familiar with OAO Corp.'s bid for a contract from Rivers' agency. But he said that Rivers, who left the agency in December to become secretary of the District and is now detailed to a nonprofit education organization, was a forceful administrator who liked to "look into things deeply."

"I would not doubt that he applied pressure at times to move things in the direction that he thought they should go -- legitimately," Mercer said.

The allegation of pressure by Rivers involves a $355,000 contract that Human Services tentatively awarded in 1984 to OAO Corp. for computer services for federally financed food and nutrition programs.

Sources said Robert H. Allison, deputy controller of Human Services, has told the FBI that after he submitted a negative financial evaluation of OAO Corp., Bernard Jarvis, the agency's controller, told him that Rivers objected to his findings and wanted him to "change his mind." Agency directors customarily play no role in preparing financial evaluations of bidders.

The sources said Allison told the FBI he refused to make a change and Jarvis supported him, telling Rivers the poor rating was justified.

In an August 1984 memo to the chief of the agency's contracts branch, Allison said OAO Corp. deserved a rating of 3 on a 10-point scale because of its financial difficulties. He described a competing bidder, Electronic Data Systems Corp., as financially sound.

Allison said in the report that the Internal Revenue Service had placed liens against nearly all of OAO Corp.'s assets in an attempt to collect back taxes totaling $7.6 million. He wrote that the company had also made nearly $600,000 in loans to its president, in part to finance his private residence.

An IRS spokesman said the IRS filed $5.6 million in liens against OAO Corp. for taxes owed between 1978 and 1982. He said the company may have made partial payments, but that it has paid none of the liens in full.

Barker said through his attorney that the company owes no back taxes. The 14-year-old company has obtained contracts worth $500 million from more than 100 federal agencies, according to company officials.

In an interview last week, Allison said he would make no public statement on Rivers' reaction to his evaluation "because that is the subject of an investigation." Jarvis said he was not challenging Allison's credibility, but "I've talked to Bob and I don't recall any attempt to put pressure on him in any way. I do remember some aspects of this . . . but never an attempt to pressure anyone to change the basic finding. I can only say whatever evaluation was presented, if it were solid and reasonable, that's what I would have put forward."

Contract documents show that despite Allison's rating, the agency selected OAO Corp. for the contract. Federal authorities, however, exercised their authority to reject the agency's choice for the federally financed contract, forcing the Human Services Department to rebid the contract the following year.

In a December 1984 letter to Rivers, Andrew P. Hornsby, then administrator of the mid-Atlantic region for the U.S. Department of Agriculture, said there was "less than 1 percent" difference in the scores awarded to the two finalists and that Electronic Data Systems Corp., which underbid OAO Corp. by $50,000, was the better choice.

Hornsby said he did not agree with Rivers that OAO Corp. should be awarded the contract "primarily because of their minority status."

In the allegations by officials with the other two agencies, the officials have told the FBI their superiors ignored their recommendations or objections about OAO Services, according to sources.

Minority Business Opportunity Commission staff member Alberto Gomez told the FBI he recommended against issuing temporary minority certification for OAO Services in 1984 because the firm appeared to him to be acting as a front for its parent company, OAO Corp., sources said.

Under the city's regulations, the parent corporation could not participate in the minority contracting program unless it qualified under strict waiver provisions, because it had headquarters outside the District in Greenbelt. Sources said Gomez believed that OAO Services, while listing its office in the city, was conducting its business from Greenbelt.

Despite Gomez's recommendation, William C. Jameson, then commission director, issued a temporary two-week certification to OAO Services on Aug. 17, 1984, qualifying it to bid on contracts set aside for minority firms and receive extra points in "open market" bidding.

OAO Services bid on that same day for a $4 million contract to provide a financial computer system for the Office of Financial Management. Bids originally were due Aug. 10, but on that day Alphonse G. Hill, then the deputy mayor for finance, postponed the deadline.

Contract documents show that two former Administrative Services employes who helped evaluate the bidders strongly questioned whether OAO Services was properly certified.

One of them, Fernando Burbano, who headed the agency's information services division, said in a February 1985 memo to then-Corporation Counsel Inez Smith Reid that he told Jameson that OAO Services had provided conflicting accounts of its relationship to the parent company. Jameson responded that Administrative Services "should respect the {commission's} certification," according to the memo.

Jameson said in an interview last year that he saw no impropriety in the certification of OAO Services. He has declined to comment further.

Jameson's successor, Maudine R. Cooper, has opened an investigation, however, telling a competitor of OAO Services in a letter Sept. 8 that the commission was probing whether OAO Services was properly certified.

Following the initial two-week certification, the firm was given a two-year certification by the commission's board.

Questions about the award of the contract to OAO Services were raised publicly in May 1985 by Jose Gutierrez, former Administrative Services director, who said that City Administrator Thomas M. Downs had ordered him to give the contract to the firm.

Downs repeatedly has denied the allegation.

In the case of a subsequent OAO Services contract to issue water and sewer bills, three Administrative Services contracting officials and Assistant Corporation Counsel James Stanford objected to a decision to increase the value of an existing contract by 50 percent and change its scope without soliciting competitive bids.

The contracting officials and Stanford argued in a March 1986 meeting that procurement regulations required new bids. However, Gwen Lewis, a top Administrative Services contracting official, favored approving the amendment to save the time that would have been required for bids, saying the mayor had made improved water and sewer billing a feature of his reelection campaign, according to participants in the meeting.

The new work was required in part because hand-held meter readers provided by another contractor did not work, according to Colin Baenziger, technical adviser for the OAO Services contract.