WASHINGTON – Democratic Sen. Jim Webb of Virginia announced Wednesday he will not seek re-election in 2012.

He joins several over Senate Democrats in calling it quits after the 112th Congress, including Sens. Kent Conrad (ND), Byron Dorgan (ND), and Joe Lieberman (CT), an independent who caucuses with Democrats.

The news was first reported by Politico's Ben Smith, who learned of it from a senior Senate source.

"It has been a great and continuing privilege to serve in the United States Senate," Webb said in a statement.

"However, after much thought and consideration I have decided to return to the private sector, where I have spent most of my professional life, and will not seek re-election in 2012."

Webb seemed likely to face former Sen. George Allen (R-VA), whom he defeated in the 2006 elections.

He was one of 23 Democrats whose seats were up for grabs in the 2012 elections, as opposed to just 10 Republicans.

Smith reported that Democratic leaders believe Democratic National Committee Chairman Tim Kaine, a former governor of Virginia, would be their top candidate to challenge Republicans for the seat. Kaine has not publicly expressed any intention of wanting it.