Actress Keira Knightley to marry rocker

Hollywood star Keira Knightley is to marry her rock star boyfriend, James Righton from Klaxons. The couple have become engaged after dating since early last year.

Oscar-nominated Knightley, 27, previously dated actor Rupert Friend for several years. She and Righton have been together for around 15 months and are said to have been introduced by their TV presenter friend Alexa Chung.

Keyboardist Righton won the Mercury Prize in 2007 with his band's debut album Myths Of The Near Future. Knightley's spokeswoman said: "I can confirm that Keira is engaged to be married to James Righton."

The details of the proposal are being kept secret. Knightley, whose movie roles have included Atonement and the first three Pirates Of The Caribbean titles, is due to begin filming her next film in the US, where she will star as a wannabe singer in Can A Song Save Your Life?.

The couple have kept their romance low-key, rarely attending celebrity events together, but have been spotted together casually on a number of occasions. Klaxons are working on a new album after releasing their second in 2010.