Blake Lively is to become a brand ambassador for Stella Mccartney.

The 'Gossip Girl' star - who is reportedly dating film star Leonardo Dicaprio - met The Fashion designer after striking up a conversation about their mutual love of vegetarianism, and will now represent the brand in her native US.

A source told The Mail on Sunday newspaper: "Like Leonardo, Blake is an animal lover and believes in cruelty-free fashion so when she met Stella at the Costume Institute gala at the Metropolitan Museum Of Art last month she found they shared many of the same ideals.

"Stella thinks Blake would be the perfect brand ambassador for her company In America."

Blake, 23, has recently been photographed wearing Stella's designs for a magazine shoot.

The actress is also an ambassador for CHANEL, signing with the iconic fashion house last year, and shooting an advertising campaign for their range of Mademoiselle bags.

Chanel creative director Karl Lagerfeld said of the young star: "She's a kind of American dream girl. I think she will become a great actress."