Florence Griffith Joyner, whose electrifying sprint times and spectacular racing outfits dazzled the track and field world last year, will announce her retirement today.

Griffith Joyner, who has been capitalizing on her 1988 success by signing several commercial endorsements worth more than $1 million and has received numerous other offers which she is pondering - deals that could be worth more millions - is expected to make her announcement at a news conference, it was learned Friday.She reportedly will retire because of all the time-consuming interests outside track and field and because she has been unable to devote time to training.

For the 1988 season, and particularly the Olympics, Griffith Joyner, 29, trained extremely hard, and it paid off with three gold medals and one silver at the Seoul Games and two world records.

At Seoul, she won the 100-meter and 200-meter dashes, and ran on the winning 400-meter relay team and the second-place 1,600-meter relay team.

Her winning time in the 200 was 21.34 seconds, shattering the world record of 21.56 she had set in the semifinals. Prior to the Games, the record was 21.71, so her achievement of lowering the record by .37 of a second in such a short space of time was astonishing.

It was similar to her performance in the U.S. Olympic trials at Indianapolis in July, when she reduced the world record in the 100 meters from 10.76 to 10.49 - a drop of .27 of a second.

No sprinter - man or woman - ever had broken a sprint record by such a huge margin.

The trials actually marked the beginning of Griffith Joyner's meteoric rise, not only in athletic achievement but in international popularity.

Just as dazzling as her times, including an American record 21.77 in the 200, were her flamboyant outfits, featuring one-legged racing suits and an "athletic negligee" in her final appearance.

In addition, she became renowned for her stunning appearance - long, lacquered fingernails, flowing black hair and a radiant, ready smile.

She was just as dominant at the Olympics, except for her attire, which was limited to the red, white and blue uniforms of the United States team. Still, she captivated audiences around the world, who watched her on television or read about her in newspapers and magazines.

Since the Games, she has been inudated with worldwide offers for television and movie parts, magazine and newspaper articles, commercial endorsements and speaking engagements.