LOS ANGELES, JUNE 10 -- Pat Riley, who guided the Los Angeles Lakers to four NBA championships in nine seasons as coach, will resign Monday and be replaced by Mike Dunleavy, an assistant with the Milwaukee Bucks the last three seasons, according to two Lakers sources.

A source said that Riley decided two weeks ago to leave but was asked by Jerry Buss, the Lakers' owner, not to announce his plans until a replacement could be found.

Dunleavy agreed to terms during the weekend, enabling the Lakers to call a Forum news conference Monday afternoon to announce the changes. Both Dunleavy, 36, and Riley, 45, are expected to attend.

"They wanted to make the announcements all at once, not string it out, because that's the way the Lakers do business," a source who declined to be identified said today. "But it made {Riley} look bad. {Riley} just wanted to end this thing on good terms."

Riley would not comment on the subject of the news conference, and neither Dunleavy nor Lakers General Manager Jerry West could be reached today.

Since deciding to leave, Riley has interviewed with NBC about becoming an analyst for the network next season. Riley also is part of a group that has developed a movie script that reportedly has been sold to a company owned by actor Michael Douglas.

Dunleavy met several times with West last week in Chicago during a pre-draft camp for college prospects and reportedly agreed to terms then. He and West were scheduled to have dinner in Los Angeles tonight.

A source at the camp in Chicago said West talked to former Chicago Bull coach Doug Collins and Dave Wohl, the former New Jersey Net coach and former Lakers assistant, in regard to the Lakers job.

Dunleavy has no NBA head coaching experience. He has been an assistant under the Bucks' Del Harris for three seasons.

West has said he is impressed with Dunleavy's basketball knowledge and rapport with players. The Lakers apparently wanted a fresh face with no previous head coaching experience.

Riley reportedly had pushed for Randy Pfund, his assistant coach, to become the new coach. But sources said Pfund was too close to Riley and that the management felt a change of philosophy was needed. West has suggested to Dunleavy that he retain Bill Bertka, Riley's longtime assistant.

When Riley replaced Paul Westhead as Lakers coach Nov. 19, 1981, he had less NBA coaching experience than Dunleavy. Riley had been Westhead's assistant for 18 months and, before that, was Chick Hearn's broadcast partner for three seasons.

........ALL WITH LAKERS

Season.....W-L.....Pct...Pos....Playoffs

1981-82...50-21....704....1.........12-2

1982-83...58-24....707....1..........8-7

1983-84...54-28....659....1.........14-7

1984-85...62-20....756....1.........15-4

1985-86...62-20....756....1..........8-6

1986-87...65-17....793....1.........15-3

1987-88...62-20....756....1.........15-9

1988-89...57-25....695....1.........11-4

1989-90...63-19....768....1..........4-5

9 years..533-194...733.... -- .......102-47

CHAMPIONSHIP SEASONS

1981-82: def. Philadelphia, 4-2

1984-85: def. Boston, 4-2

1986-87: def. Boston, 4-2

1987-88: def. Detroit, 4-3