D.C. Police Chief Burtell M. Jefferson called an extraordinary midday press conference yesterday to deny point by point a published report that he would retire by Oct. 1.

The Washington Star reported yesterday that Jefferson had made a "mutual" agreement with Mayor Marion Barry to leave by that date. Deputy and assistant police chiefs had already been told they are "under evaluation" as possible successors, The Star reported.

"Let me tell you something," Jefferson told a crowded conference room of reporters and high-ranking police officials at the Municipal Center, "The mayor doesn't make any mutual agreements with anyone. He has a right to remove me from office if he wants to or he has a right to keep me."

"And so far, he has kept me and hasn't said anything about removing me."

Later, in the day Ivanhoe Donaldson, the mayor's general assistant and chief of staff, echoed Jefferson's assertion.

"He's Marion Barry's police chief," Donaldson said, hoping to put an end to allegations that have nagged the new administration for months. "The chief has a place in this administration as police chief - as long as I have a place in the administration." $&(WORD ILLEGIBLE

"All of these innuendoes and rumors floating in and around the police department are just that," Donaldson said, "and we can't respond to them every time they pop up."

Friction between Jefferson, a 31-year police veteran with a by-the-book style of running a traditionally independent police force, and Barry, a newly elected activist mayor with a desire to take a personal hand in all city operations, first surfaced in May.

The Washington Post reported May 31 that Jefferson had told friends he was distressed and angry because he felt Barry was interfering in the operations of the department, and that some of the mayor's actions had undercut the chief's authority. At that time, Jefferson denied making the statements and blamed the press for spreading "innuendo."

The sources said then that Jefferson was considering resignation. Jefferson denied then that he was considering resigning and repeated the denial yesterday.

Several sources in the police department said yesterday that since the difficulties earlier in the year, the chief and Barry have become more accustomed to one another's styles and have worked more closely together.

"Jeff has been a lot more aggressive and more secure," one high-ranking police official said privately. "Not that many major issues have occurred since then. The mayor and city administrator's office have adopted a lower profile. There's no longer a barrage of calls from them telling you what to do."

At yesterday's press conference, Jefferson read from The Star article, denying each paragraph.

Points on which he and Barry were reported to disagree, they agreed on, Jefferson said. The mayor had never overruled him as reported, he said.

In order to answer published reports that several assistant and deputy chiefs had been told they were under evaluation, Jefferson asked reporters to quiz those present. Two chiefs volunteered that they had not been told that, and others present nodded in agreement.,

Jefferson said many policemen were considering retiring by Oct. 1 in order to avoid being covered by a law, which becomes effective Jan. 1, that will place tighter restrictions on retired policemen receiving full pension benefits while holding down post-retirment jobs.

"A lot of officers don't want to be caught in that trap," Jefferson said. "But as far as I am concerned, I have no intention of retiring."

"I think the mayor is going to be around until 1982," Jefferson said. "And unless the mayor changes his mind, I'm going to be chief of police until then." CAPTION: Picture, BURTELL M. JEFFERSON..."so far he has kept me"