Megan Fox is back on the singles market after ending her three year engagement to fiance Bryan Austin Green, according to the latest reports.

The Transformers star - who was named the World's Sexiest Woman in 2008 - is said to have ended her relationship with the former Beverly Hills 901210 star so they can both focus on their prospective careers - or, at least, that is the official line.

The couple met in 2004 and two years later they officially declared their plans to marry, but now it seems the honeymoon period is over.

Insiders have told Us Weekly that "the relationship had run its course.

"It's completely amicable, and they are remaining friends. They are now both focusing on their careers."

Megan is likely to set pulses racing on the big screen when she reprises her role as Mikaela in Transformers sequel Revenge of the Fallen.

See why Megan was named sexiest woman below