Chris Noth and Tara Wilson at Entertainment Weekly's Oscar Viewing Party in New York City on March 5, 2006. [Agencies]

Chris Noth's long-term girlfriend Tara Wilson has given birth to the couple's first son.

The actor, who plays Carrie's lover Mr Big in Sex and the City, welcomed Orion Christopher into the world in LA on Friday.

His spokesperson told People that the baby weighed in at 7 pounds, 10 ounces.

Noth, 53, is currently shooting the Sex and the City movie alongside Sarah Jessica Parker.

He also stars as Detective Mike Logan in NBC's legal drama Law & Order: Criminal Intent.

Parker told Entertainment Tonight: "I'm thrilled for him because I think, first of all, he's going to make a wonderful, wonderful father.

"He's found a lovely lady to have a child with. It's the perfect time for him and I think he's very ready."