BALTIMORE, MAY 31 -- Bob Manfuso plans to be at Pimlico Saturday, which is nothing new in his 3 1/2 years as co-owner of the track. But something about it will be very different.

Manfuso is going to watch the performance of Jeweler's Choice, a horse from the Fourbros Stable he operates with his brother, Tom, also a part-owner of Pimlico and Laurel. If not for Jeweler's Choice, Manfuso would have little reason to be at Pimlico. Today, he and Tom officially resigned from active management, a move they had announced in February.

The Manfusos, together the largest equity owners in the combined operations of Pimlico and Laurel, have had few days off since they bought Laurel with Frank De Francis in December 1984, but that's about to change drastically. Except for monthly meetings of the board of directors -- on which they'll remain active and involved -- they have removed themselves from the day-to-day operations, Tom supervising the physical plant, Bob the quality of horses and racing schedule.

"If there's some special project and they feel I could be of some assistance, I'd certainly be glad to contribute whatever I can," Tom Manfuso said. "Day-to-day management is something I always felt required nothing less than a total commitment. To a great extent we've accomplished in the last 5 1/2 years the goals we established. Now it's a matter of maintaining that growth and being able to compete effectively when OTB {off-track betting} parlors in Pennsylvania and racing in Virginia occur."

Tom Manfuso said he had promised De Francis five years of service when they bought Laurel in 1984. He said he would have left the daily responsibilities had De Francis not died last August, and restated that this departure is not a step toward selling one or both tracks.

Joe De Francis, who replaced his father as chief executive officer of the tracks, has not said how the jobs will be filled.

"I would have preferred to do this in January, but with Joe coming in we couldn't, without creating the perception that we were leaving because of a lack of support for him," Tom Manfuso said. "We stayed through the Preakness to make sure everything went smoothly; it would have been an unfair burden to put on his shoulders."

Bob Manfuso will be spending most of his time completing Chanceland Farm, a 195-acre residence and breeding farm in Howard County that will feature a full-size training track. "I've got lots of things scheduled for the next three weeks, so I haven't had a shot to sit back and reflect on how I feel about all this," he said.

While Bob is at Pimlico Saturday, Tom will be at his summer home on Kent Island. He said he'll become more involved in family business matters and spend more time with his wife and on the golf course.

"I love this business so much, I'm going to miss not being involved every day," Tom Manfuso said. "But will I be happier doing what I'm doing? Probably, yes." A 'Notion' Two

Fighting Notion, one of Maryland's top 3-year-olds, prepared for the Ohio Derby with a second-place finish today in his first race against older horses.

Fighting Notion set a much faster pace than he did in the Preakness Stakes, in which he led until the stretch and finished fifth. But Macau, who raced off the pace in third, caught Fighting Notion as they straightened for home. Macau scored a six-length victory over Fighting Notion, the strong favorite.