Boston (AFP) - American forward Paul Pierce signed a one-day contract with the Boston Celtics on Monday in a move that allows him to retire as a member of the National Basketball Association (NBA) franchise.

The 39-year-old spent the first 15 years of his career with Boston, helping the club to a league championship in 2008.

"It's an honour to have this opportunity to once again call myself a Boston Celtic," said Pierce, a 10-time All Star.

"The organisation and city took me in and made me one of their own, and I couldn't imagine ending my career any other way.

"I'm a Celtic for life."

Team owner Wyc Grousbeck said they also plan to retire Pierce's No. 34 jersey.

Pierce averaged 19.7 points and 3.5 assists while playing in 1,343 career games with the Celtics, Brooklyn Nets, Washington Wizards and Los Angeles Clippers.