Uma Thurman
Expectant: Uma Thurman at 41 Reuters

Kill Bill star Uma Thurman is preparing to become a mother for the third time after announcing she is pregnant.

The 41-year-old Hollywood actress is expecting her first child with her partner, financier Arpad Busson, according to People magazine.

Thurman will in the growing list of celebrity mums over 40 which includes Courteney Cox Arquette and Halle Berry.

The couple, who began dating in 2007, both have children from previous relationships.

Thurman is mother to Maya, 13, and Levon, 10, from her marriage to Ethan Hawke. Busson has two children - Arpad Flynn Alexander, 14, and Aurelius Cy Andrea, nine, with former girlfriend Australian supermodel Elle Macpherson.

Thurman concealed her growing lump when she stepped out for New York Fashion Week in a loose navy outfit and matching coat.

She is working on upcoming drama series Smash.