Carmen Electra has called off her engagement to Rob Patterson.

The 40-year-old actress and model is said to have broken off plans to marry The Rock guitarist after a four-year engagement and they have reportedly been living separate lives for some time.

A source told Life & Style magazine: ''It's off. She hasn't been wearing her ring for a while, but they're good friends and it's been really hard for them to fully separate.

''They're more like roommates. They don't share a bedroom anymore and they sleep in separate parts of her house.''

News of the split comes on the same day Carmen has confirmed she will appear on a new dating show, 'The Choice', where ordinary people pitch themselves forward for the opportunity to date celebrities.

The source added: ''Carmen's really nervous about getting back into the dating pool, so keeping Rob around makes her feel less anxious about being single. It's not like they'll get back together. The romance part is dead. They're done.''

Carmen has been married twice previously, to retired basketball player Dennis Rodman and Jane's Addiction guitarist Dave Navarro.

Rob and Carmen announced their engagement at her 36th birthday party in Las Vegas in 2008.

Shortly afterward she said they were planning to take their engagement slowly, saying: ''You have to stay connected and make an effort. We're taking it slow and have no wedding date yet. We have been friends for eight years. We connect on a lot of different levels.''