Robin Thicke and Paula Patton
Robin Thicke and Paula PattonReuters

Paula Patton has officially filed for divorce from her estranged husband Robin Thicke, ending their nine years of marriage.

The 38-year-old actress cited "irreconcilable differences" for the divorce and mentioned the date of separation as 21 February, according to TMZ. Sources told the publication that the divorce is "harmonious." 

Patton wants joint legal and physical custody of their son Julian Fuego Thicke, who has turned four, giving a hint of an amicable separation.

Thicke, 37, and Patton announced their decision to split in February this year.

"We will always love each other and be best friends. However, we have mutually decided to separate at this time," the couple had said in a joint statement.

"We've known each other since we were teenagers," Patton told Vanity Fair in May. "All I can tell you is there's a deep love there – always was, and always will be." 

Thicke apparently tried to save his marriage but couldn't. In what looked like an attempt to win Patton back, he did an emotional music video of his new song, "Get Her Back" before releasing his seventh studio album, Paula, in July but nothing worked.

He also publicly apologised to his wife saying, "I'd like to dedicate this song to my wife, and say, 'I miss you, and I'm sorry.' This is called 'Forever Love'," on stage before performing to the song at the BET Awards 2014. 

"Robin wanted to save their marriage, but it was Paula's choice and she ended it," a source had earlier told Us Weekly. "Robin does not want this divorce." 

Another source added that the high school sweethearts, who tied the knot in 2005, were "figuring things out" though Patton had made it clear that it was all over.