Prince George's County Corrections Director Arnett Gaston, in a letter of resignation submitted yesterday, blamed his problems in running the troubled county jail on supervisors there who "manipulate the system to avoid being held responsible for their incompetence and unwillingness to work."

Gaston also said he resigned because he felt he could no longer work with certain jail employes who he maintained interfered with his efforts to improve the jail.

"It has become evident . . .that some elements will, for vested and personal reasons, continue in their attempts to impede improvement," Gaston wrote.

Although he did not name the employes, jail sources said that at least two high-ranking jail officials did not always inform Gaston of problems within the institution, and did not correct the problems themselves. The sources said, however, that Gaston did not always want to know about problems in the institution, and in at least one instance documented in jail records did not support Gerald Rice, former director of security, when Rice wrote him a detailed memo April 30, 1981, asking that Gaston charge Edward Blakeslee, a shift commander at the time, with insubordination.

Gaston said he took over a system (in 1979) that had "monumental" problems. Among those were "one of the severest problems of overcrowding in the country," he said, and workers at the jail who had criminal records "more serious than some of the people incarcerated . . ."

There are currently at least four guards at the jail who have been charged with and/or convicted of crimes, according to internal jail documents. The crimes include soliciting without a license, larceny, and welfare fraud. One of the guards was hired by Gaston.

Prior to Gaston's term at the jail, 15 guards with criminal records worked there, according to internal jail documents. Most of those guards were fired for their actions during the August 1980 guards' strike.

Gaston's statement was his first since rumors surfaced earlier in the week of his impending dismissal or resignation. His management of the jail had come under fire after an escape and attempted escape last summer and a Washington Post series last fall that said male rapes and sexual assaults occurred frequently in the Upper Marlboro facility. Neither Gaston, nor his chief spokesman, could be reached for comment yesterday.

County Executive Parris Glendening, who announced Gaston's resignation, used yesterday's press conference at the jail as a forum to discuss the improvements he plans to make there. He said he would begin an immediate nationwide search for Gaston's replacement, move quickly to build a new jail that is already in the planning stage, and persuade the County Council to take more of an interest in jail operations.

Glendening released an audit by the National Sheriffs' Association that was highly critical of the jail. "The problem lies not only with the first-line supervisors, but from top to bottom, beginning with the director of the center," the audit said.

Sources close to Glendening said the county executive had been hoping for some time that Gaston would leave quietly, especially after he saw a preliminary draft of the sheriff's report. When that did not work, according to sources, Gaston had to be "persuaded" to leave.

"He had to be persuaded of the seriousness of the situation," said one source, and "that the public wouldn't allow these reports to ride and neither could we."

Glendening and his chief administrative officer, John Wesley White, have maintained publicly that Gaston's decision to resign was agreed upon mutually.

Yesterday, White said of Gaston's letter, "I don't have any fundamental disagreement with anything he says." Of the reference to individuals with criminal records, White said, "I think there have been a few isolated incidents where those things have been detected and corrected."

But of Gaston's complaint about a lack of support by supervisors, White said, "If that existed I would hope that more direct action would have been taken--by Gaston. It's really the facility director's responsibility not only to discover it, but to remedy it."

White described Gaston as "very frustrated and angry with the convergence of circumstances" that led to his resignation. But, White added, Gaston has "certainly carried himself very professionally in this affair."