A large part of corporate America, 94%, don't offer employees benefits coverage for domestic partners -- unmarried people who live together in a financial relationship. (According to human resources consulting firm Buck Consultants Inc., there are 5.6 million households in the U.S. headed by unmarried couples, about one-third of them same-sex couples.) However, 29% of the more than 1,000 employers surveyed by the New York-based firm say they are considering such benefits even though there have been efforts by Congress to prevent such coverage, particularly for same-sex couples. One of their biggest motivations for companies: fear of employee discrimination claims based on sexual orientation or marital status. Of the employers who do not offer domestic partner benefits, 56% told Buck that they perceived no employee interest in such a program, and 21% cited moral objections to it. (Some gave more than one reason.) Two-thirds of the companies surveyed had 500 or more employees.