Matt LeBlanc will play his old Friends character Joey in his new show

De Matteo, 32, who plays mafia moll Adriana LaCerva in the TV gangster drama, will play LeBlanc's older sister Gina in the Friends spin-off show.

"It was very, very unexpected. I never even had the chance to think about it," said the actress.

She did not rule out continuing her role in The Sopranos' final series, which begins filming next March.

"I play a hairdresser - my character is very similar in look and accent to Adriana, but sharper and tougher," said De Matteo.

"Matt (LeBlanc) is a great guy and I couldn't have asked for a better actor to fall into the hands of," she added.

End of an era

Joey is expected to begin in the US this autumn in the Thursday evening slot that was occupied by Friends.

Three members of the Friends creative team - executive producers Kevin Bright, Scott Silveri and Shana Goldberg-Meehan - are working on Joey.

LeBlanc's new contract also includes plans for him to star in two feature films made by Warner Bros Pictures, makers of Friends and Joey.

The emotional finale of Friends was watched by 51 million people in the US last week.