BOWLING GREEN, Ohio (AP) - Bowling Green will eliminate four men's sports to comply with a federal law designed to equalize the money colleges spend on men's and women's teams.     Men's tennis, swimming and indoor and outdoor track and field will be dropped starting in the fall, the school said Thursday. The move will cut 55 scholarships and save $360,000 each year, athletic director Paul Krebs said.     "This has been an extremely difficult and heart-wrenching decision,'' said Krebs, who added that the university had been talking about eliminating sports for at least three years.     The decision leaves the school with eight men's sports and 11 women's sports.     According to Title IX, a 1972 federal law, schools must offer scholarships roughly equal to the number of men and women on campus. About 56 percent of the students at Bowling Green are women.     Athletes on the teams cut will keep their scholarships through the next school year.     Complying with gender equity laws has been a challenge for schools in the Mid-American Conference. Miami of Ohio dropped three teams in 1999, prompting male athletes to sue the school.     Bowling Green already had dropped wrestling and men's lacrosse.