United Airlines' decision is expected to put pressure on other major employers to offer the same package to their gay employees.

Gay rights activists protested against United's earlier refusal to grant gay partners equal benefits rights

United made the offer after a federal court in San Francisco ruled that a group of US airlines were not exempt from the city's domestic partners ordinance requiring companies doing business in San Francisco to provide benefits to life partners of employees regardless of sexual orientation.

United, along with other airlines, had been fighting the ordinance on the grounds that it was open to abuse and that it would be difficult to monitor.

In making the decison to award its gay employees the same partner benefits rights, United said its decision did not amount to compliance with the San Francisco ordinance and that the challenge to it would continue in the appeal courts.

Move welcomed

United Airlines chairman James Goodwin said the case had not been about gay rights, but about opposition to local legislatures attempting to impose rules on a national organisation.

He said: "We value diversity at United, both among our employees and among our customers.

"We are not merely complying with the San Francisco ordinance as the court has ruled, but are offering a broader package of domestic-partner benefits to our employees and retirees."

United is expected to make the benefits available in the US next year, and to introduce the package worldwide in the future.

The move has been welcomed by gay rights groups.

Nick Morse, executive director of United's gay employees group United With Pride, said: "We are ecstatic to hear the news.

"Since the outset of this situation, we have seen communities become polarized around this issue.

"With this step, I hope we can begin moving forward together - United, its employees, the city of San Francisco and the gay and lesbian community at large."