Harrah's Entertainment has called for an override if Gibbons vetoed the measure.

The casino giant pointed to an estimated $700 billion in buying power among potential lesbian, gay, bisexual and transgender customers.

The bill also had support from of the powerful Nevada Resort Association, and drew praise from the American Civil Liberties Union of Nevada.

Gary Peck, ACLU executive in Las Vegas, called domestic partnership rights an economic and civil rights issue.