A bill to extend domestic partnership rights to gay couples in the US state of Wyoming has been defeated.

The Republican-controlled house in Cheyenne voted down a bill on Wednesday night that would have given same-sex couples the same legal rights as heterosexuals.

The defeat was a stinging blow to supporters of the legislation.

Jackson Republican Representative Ruth Ann Petroff, a co-sponsor of House Bill 168, said it was unlikely the bill would re-emerge during this legislative session.

“I had a feeling that this was going to be the time that we could get this through. Obviously, it wasn’t,” she said.

The vote was 25-34 and came two days after a measure that would have allowed same-sex marriages also failed.

In the debate leading up to Wednesday night’s defeat, State Representative Mark Baker claimed that “only 1% of homosexuals die of old age” and that domestic partnerships would cause higher health care costs for the state.

Mr Baker also said that domestic partnerships were not “rooted” in the Wyoming constitution or in the cowboy state’s tradition.

The legislation would have clarified how the state deals with same-sex couples and domestic partners in matters such as child custody and inheritance.