Even though Massachusetts recognizes the legality of gay marriages, some employers have refused to extend health benefits to the spouses of gay workers - opting instead to follow guidelines in the federal 'Defense of Marriage' Act. Signed into law by President Clinton, the act defines marriage as a union between a man and a woman. General Dynamics, FedEx and Caritas Christi Health Care are among the companies refusing to grant equal health care coverage. Gay and lesbian advocacy groups plan to challenge the action in court.