Few US pastors have been asked to officiate a same-sex wedding since the Supreme Court allowed gay marriage last year, according to new research.

Only 11 per cent of pastors surveyed by LifeWay Research said that they had been asked to conduct a wedding ceremony for gay couples. Just 1 per cent of Baptist pastors have been asked, though 26 per cent of Presbyterian/Reformed pastors have had requests.

Since the historic ruling last year, around 100,000 same-sex weddings have taken place, according to LifeWay.

In general, pastors who called themselves 'mainline' were three times more likely to have been asked than those who describe themselves as 'evangelical'; and older pastors were more likely to be asked than those under the age of 54.

"Most couples, if they want a church wedding, will ask a pastor they know or who they think will support them," said Scott McConnell, the executive director of LifeWay Research, in a statement. "For same-sex couples, this appears to be an older Presbyterian pastor."

LifeWay Research asked 1,000 senior Protestant pastors their views on LGBT issues in March for the survey. A third of those asked said that gay people cannot serve in their church, while a similar number said that they are welcome to serve in any capacity. Those most likely to be happy for LGBT people to serve are the Presbyterian/Reformed and Methodists, while Baptists and Pentecostals are least likely to share that view.

Overall the pastors were most happy for gay people to fill a helping or serving role, but less keen on their leading worship, teaching or holding other leadership roles.

The research didn't disclose how LGBT had been defined, or whether a commitment to celibacy would have made a difference to the pastors' decisions.