Mayor Marion Barry yesterday blocked implementation of controversial new guidelines that would allow District of Columbia police officers to engage in part-time work as private security guards.

Several opponents of the measure spoke briefly with Barry Thursday night and about 70 private security guards who said they fear losing their jobs to city policemen protested outside the District Building yesterday morning, shortly before D.C. Police Chief Maurice T. Turner was instructed to delay issuing the general order.

However, City Administrator Elijah B. Rogers said the delay was ordered after the D.C. Office of Documents questioned whether, by law, the guidelines must first be published in the D.C. Register and undergo public review for 30 days before being put into effect. He said the protests had nothing to do with the decision.

The guidelines were drafted by the police department to implement a law passed last June aimed at helping to curb crime in the city by posting more armed and uniformed officers in public places.

"New rules to implement any action of the City Council establishing new policy must first be published," Rogers explained. "There's no stonewalling or anything like that."

D.C. Police Officer Gary Hankins, head of the labor committee of the Fraternal Order of Police (FOP), said he was aggravated because this was the second time that the Barry administration has held up implementation of the guidelines.

Hankins contends that the guidelines are an internal police department matter that don't require publication, but Rogers disagrees. Judith W. Rogers, the D.C. corporation counsel, has been asked by the city administrator to resolve the legal dispute next week.

"We want it done as quickly as possible," Hankins said.

The regulations would allow police with the rank of captain and below a maximum of 24 hours a week of part-time work. Opponents of the measure, including the D.C. Security Association and the 70-member Afro-American Police Association, suggest that as many as 2,000 D.C. police officers may compete with them for jobs.

"We feel close to 1,200 of our people will lose their jobs because of this, and these are low-paid people, blacks, who mostly are paid minimum wage," said Michael O. Revel, president of Revel's Security Agency.

Opponents are particularly concerned about what they consider to be unfair competition from a job bank or referral service that has been set up by the FOP, the bargaining agent for rank-and-file city policemen, to place members in private security jobs.

Revel and other members of the D.C. Security Association who met with Barry Thursday night said the mayor promised that the guidelines would not be issued until Barry fully reviews issues surrounding the guidelines and meets again with them.

Turner said late yesterday that he wasn't upset by the delay and that he was awaiting a memo from Elijah Rogers outlining the legal requirements for publishing the guidelines.

The chief contended that, once implemented, the measure would prove to be helpful in combating crime. "It's a deterrent to crime to have high visibility police officers in uniform out in the community," Turner said.