Fairfax County's chief purchasing agent charged yesterday that top county officials asked him to resign after he uncovered a pattern of irregularities and mismanagement in the awarding of county contracts.

"I began finding irregularities in purchasing since the first day I got there," said Charles J. Cedeno, who took the post last July after extensive experience in private industry.

Cedeno said that cost overruns and improprieties in bidding procedures, ranging from office furniture for some county supervisors to a multi-million-dollar landfill contract, were routine in the county, which prides itself on clean and efficient government.

In one instance, Cedeno said, a $40,000 contract for microfilm equipment for the Fairfax circuit court clerk's office was awarded to the highest bidder, Eastman Kodak Co., at the urging of the clerk's office. Cedeno said he later discovered the equipment was delivered more than two months before the competitive bids were opened.

In another case, Cedeno said, a $400,000 contract for landfill dirt turned into a $2 million award for a private contractor after the contract was repeatedly extended without competitive bidding.

"They start with a small purchase, but then they keep renewing it [the contract] and it grows like a big balloon," Cedeno, 44, said.

A senior county official yesterday denied that the request for Cedeno's resignation was related to his allegations about purchasing improprieties.

Fred K. Kramer, director of the county's general services department and Cedeno's boss, said county officials found that Cedeno used "Significant vulgarities" in staff meetings, had been heavy-handed and undiplomatic in his criticism of county employes, and was incapable of handling personnel matters.

Kramer said the resignation decision had nothing to do with Cedeno's technical capabilities or his charges about errors committed by the staff.

Cedeno, who makes $31,500 a year in the job, has been summoned to a meeting this morning with county officials to discuss his departure.

Cedeno said he also found that the county often paid up to 10 percent in excess charges on contracts with little or no scrutiny by officials as to the reasons for the overruns. "If a $100,000 contract came to $105,000, it would get paid," he said.

Cedeno said two county supervisors did not follow normal purchasing procedures in buying furniture for their district offices.

In one instance, he said, Sandra L. Duckworth, a Democrat representing the Mount Vernon district, sent back three secretarial chairs issued to her by the county and instead bought three chairs on her own for $400. Duckworth, who told a reporter the county-issued chairs were "just crummy," sent the $400 bill to the county.

The second supervisor, James M. Scott (D-Providence) purchased more than $1,000 in office furniture from a dealer who was not under contract to the county.

Both Scott and Duckworth said over the weekend they were unaware that county regulations require that all purchases be handled directly by the purchasing department.

Scott said he consulted with county officials before buying the furniture and was told he should compare prices, but was never told he must make the purchase through the county -- an assertion which Cedeno contradicts.

Cedeno acknowledged in an interview that he curses openly and has a blunt management style. "I'm drastic, that's the truth," said Cedeno, who was born in Venezuela. But Cedeno said Kramer and others have known about his style for months, and are trying to oust him now because of his persistent questioning of county purchasing practices.

"Somebody has been trying to stop me for a long time, but they have not been able to find a way to do it," he said. "Now they have finally found a way."

Cedeno said he strongly complained about what he felt was improper purchasing of microfilm equipment by Circuit Court clerk James E. Hoofnagle's office. Besides the $40,000 in equipment that was delivered early, he said, another $60,000 in equipment was purchased without proper competitive bidding.

In a draft memo sent to Cedeno and other county officials in April, Hoofnagle said he and his special assistant, Joseph O'Connor, who was directly responsible for the purchases, "regret our violation of procurement regulations and assure you of our strict compliance in the future. . . ."

All of the microfilm equipment was purchased from the same company -- Kodak -- according to county records.

The purchases began in January 1978 when the clerk's office bought a $6,256 microfilm camera from Kodak as a "sole source purchase" without competitive bidding, according to county records. In a Jan. 10, 1978, memo to purchasing officials issued under Hoofnagle's name and signed by his special assistant, O'Connor, the purchase was justified on grounds that Kodak had the best available equipment.

On the one occasion when bids were solicited, in December 1978, the clerk's office again asked that Kodak get the nearly $40,000 contract, even though its bid was more than $15,000 higher than the lowest bid, according to Cedeno.

Cedeno, who was not employed by the county at the time, later discovered that Kodak had actually shipped the equipment to the clerk's office in September 1978, more than two months before the bids were opened, prompting Cedeno to call it an "apparent phony bid."

Hoofnagle yesterday referred all inquiries to his assistant, O'Connor, saying that O'Connor was in charge of the purchases.

"Everybody draws a blank on this," O'Connor said when asked how the equipment could be shipped before the contract was awarded. O'Connor said he was unaware that the equipment had been delivered until long after it arrived, and assumes a secretary in the clerk's office incorrectly accepted it. He said he found the equipment on a courthouse loading dock, but that the boxes were not opened until the contract was awarded to Kodak.

O'Connor said he did not order the equipment to be delivered ahead of time. "We don't have authority . . . to go out on our own and buy equipment per se. We go through the county purchasing system," O'Connor said.

In December 1979 the clerk's office again purchased microfilm equipment, this time about $50,000 worth, from Kodak without competitive bidding, according to county records Kodak's invoice shows that the equipment was ordered in October 1979, more than two months before the purchasing department authorized the "sole-source" purchase, Cedeno said.

A personnel investigation of Cedeno was initiated by the county after Cedeno took away purchasing authority last month from deputy purchasing agent Charles A. Tedesco, according to Kramer. Tedesco, a longtime county employe and runnerup to Cedeno for the top purchasing job, hired a lawyer and submitted allegations to the county about Cedeno's job behavior, Kramer said.

Cedeno said he ressigned Tedesco because Tedesco had approved purchases without following proper county procedures. Tedesco could not be reached for comment yesterday.

Before hiring Cedeno, county officials conducted an exhaustive check of his background, including sending a police investigator to Philaelphia, where Cedeno was employed.

Cedeno, the author of the books on purchasing and a number of trade journal articles, was an instructor in purchasing at Drexel University and said he has been invited to lecture at the University of Virginia. He was also an adviser to the American Bar Association on the model procurement code.

Cedeno was director of purchasing for the Southeastern Pennsylvania Transportation Authority before being hired by Fairfax, and has worked for several private companies.

Cedeno, who has hired a lawyer, said he plans to continue as purchasing chief, if the county will let him remain.

"I want the county to let me finish my job and let me get a professional purchasing department," Cedeno said. Instead, they want to stop me. Why?"