Kate Bosworth flashes engagement ring

Kate Bosworth has been referring to her partner as her 'fiancé' for a few weeks now, but it was made official yesterday when she stepped out wearing an engagement ring for the first time.

Kate and Michael Polish, her boyfriend of one year, looked blissfully happy as they strolled around New York, stopping occasionally to gaze into each other's eyes, have a cuddle or give their pert derrieres a little squeeze.

The Superman Returns actress helpfully held her hand to her face, showing of her ring featuring an enormous square-cut diamond, for the photographers.

She confirmed the engagement on Twitter, posting a photo of herself wearing the ring with the message: "This photo was taken by my husband-to-be! Thank you all for the wonderful engagement wishes... We feel truly blessed."

Kate's lucky man is a director and writer; they met on the set of her next film, Big Sur. She previously dated True Blood star Alexander Skarsgård, and before that was with Orlando Bloom for three years.