ANN ARBOR, Michigan, June 6. TRAINING and preparation for the upcoming Santa Clara International and United States Nationals have forced Michael Phelps to withdraw from the Mare Nostrum Series, the three-stop European stretch that annually attracts some of the elite swimmers in the world. Phelps was originally slated to compete in France, Italy and Monaco. "The Mare Nostrum series is a great event and we are extremely disappointed that Michael has to withdraw from it at this time," said Phelps' coach, Bob Bowman, in a release sent to the media by Octagon, the firm that represents Phelps. "In looking at Michael's goals for the rest of this summer and beyond, we feel that it would be best for him to continue our training program within his normal routine and environment." In Melbourne earlier this year, Phelps put on one of the finest exhibitions the sport has seen, winning gold in seven events and setting five world records. Phelps established global standards in the 200 butterfly, 200 freestyle, 200 individual medley, 400 I.M. and as a member of the American 800 free relay.