Sources: Trade deadline is March 15

NBA teams were informed Friday that the trade deadline for the 2011-12 season will be March 15, sources told ESPN.com.

The deadline falls roughly three weeks later than usual, with the season starting on Christmas Day. The trade deadline typically fell on the first Thursday after the All-Star Game in the previous labor agreement.

NBA front-office sources said Friday that the league also has informed teams that the seven-day window to invoke the new amnesty clause is Friday through Dec. 16.

Roster moves in the NBA were permissible as of 2 p.m. ET Friday.

In other key dates established by the league for the truncated 66-game season, 10-day contracts can be signed starting Feb. 6; non-guaranteed contracts become guaranteed Feb. 10; and the last day to sign a player and have him be playoff-eligible is March 23.

Between Dec. 25 and Feb. 6, teams will be able to dress and play 13 players instead of the usual 12. After Feb. 6, teams can dress 13 players but only 12 can play.

Marc Stein is a senior NBA writer for ESPN.com.