PARIS (AFP) - About 7,000 same-sex couples tied the knot in France last year after gay marriage was legalised in May, the national statistics agency said on Tuesday.

France legalised same-sex marriage after months of intense and sometimes violent protests, in keeping with an election pledge by Socialist President Francois Hollande, who faced a huge backlash from the opposition right and the powerful Catholic Church.

Same-sex unions made up around three per cent of the total number of 238,000 marriages registered in France in 2013, the Insee statistics agency said.

Three out of every five gay marriages involved male couples, it said.

The average age at which male gay men got married was 50, while it was 43 for women. The corresponding average age for heterosexual couples was 37 and 34.

The first gay marriage in France was held on May 29 in the southern city of Montpellier, which has a gay-friendly reputation.

But many die-hard conservatives have continued to oppose the measure. Some mayors argue that the lack of an option not to perform gay marriages violates the French constitution, which stipulates that freedom of conscience is a fundamental human right.

Several have refused to conduct gay marriages on the grounds it goes against their beliefs, but the Constitutional Council, France's top court, has ruled they cannot do this.