Reality star and businesswoman Kim Kardashian on Friday filed for divorce from her rapper husband Kanye West after almost seven years of marriage and months of rumours that their relationship had broken down.

Representatives for Los Angeles Superior Court and for Kardashian, 40, said she had filed the divorce papers.

Celebrity website TMZ cited unidentified sources as saying the split was amicable and that Kardashian had asked for joint custody of the couple’s four children. The grounds for the divorce were not immediately known.

Representatives for West did not immediately return a request for comment.

The filing follows months of leaks and reports that the marriage between the two celebrities was on the rocks.

Kardashian, who made her name in the reality TV series “Keeping Up with the Kardashians,” married West, 43, in May 2014, making them one of the biggest celebrity couples in Hollywood and popularly known as “Kimye”.

The couple’s already unconventional relationship became strained last year when West, who suffers from bipolar disorder, ran an unsuccessful campaign marked by erratic statements to be elected U.S. president under his self-styled Birthday Party.

Kardashian in July released a statement urging compassion for West’s mental health struggles. But the couple appeared to grow further apart with the 21-time Grammy winner spending most of his time at his ranch in Wyoming and Kardashian remaining in their Calabasas mansion outside Los Angeles.

Both Kardashian and West are reported to be billionaires. West made his money through his music as well as his Yeezy fashion and sneaker line.

Kardashian, who is training to be a social justice lawyer, made her money through her TV series, as a social media influencer, and by developing a lucrative line of cosmetics and foundation garments.

TMZ reported that the couple had a prenuptial agreement and that discussions on a property settlement were well advanced.

The wedding was the first for West and the third for Kardashian after she had brief marriages with basketball player Kris Humphries and music producer Damon Thomas.

By Jill Serjeant and Dan Whitcomb