C's make Williams signing official

The Boston Celtics formally announced the signing of forward/center Sean Williams and requested waivers on center Jermaine O'Neal.

From the team's press release:

Williams, a 6-10 center/forward, appeared in eight games for the Dallas Mavericks this season averaging 3.6 points and 1.6 rebounds per game. The product of Boston College also appeared in 27 games for the Texas Legends of the NBA Development League this season averaging 15.2 points, 8.9 rebounds and 2.5 blocks per game. Williams was originally drafted by the New Jersey Nets with the 17th overall pick in the 2007 NBA Draft and has posted career averages of 4.3 points, 3.4 rebounds and 1.2 blocks in 134 career games split between New Jersey and Dallas. Williams was named to the NBA’s 2008 Rookie/Sophomore game and recorded 17 points and 10 rebounds in the contest. He recorded his best statistical season as a rookie with the Nets when he averaged 5.6 points, 4.4 rebounds and 1.45 blocks per game.