Keira Knightley is to marry her rock star boyfriend James Righton.

The Hollywood actress and the Klaxons rocker have got engaged after dating since early last year, it has been confirmed.

Keira's spokeswoman said: "I can confirm that Keira is engaged to be married to James Righton."

The details of the proposal are being kept under wraps.

Her publicist added: "We are not discussing any further details."

Oscar-nominated Keira, 27, and James have been together for around 15 months and are said to have been introduced by their TV presenter friend Alexa Chung.

The couple have kept their romance low-key, rarely attending celebrity events together, but they have been spotted together casually on a number of occasions.

Oscar-nominated Keira previously dated actor Rupert Friend for several years.

The star, whose movie roles have included Atonement and the first three Pirates Of The Caribbean titles, is due to begin shooting her next film in the US. She will star as a wannabe singer in Can A Song Save Your Life?.

Keyboardist James won the Mercury Prize in 2007 with his band's debut album Myths Of The Near Future. Klaxons are working on a new album after releasing their second in 2010.