The National Basketball Association has notified teams that regular season games through to Dec. 15 have been canceled because of the labor dispute that has locked out players for nearly five months, a league spokesman said on Tuesday.The NBA had already scrapped the first month of a regular season that was originally scheduled to begin Nov. 1 and the latest move came a day after players rejected a contract offer that included plans for a shortened season. Only the first month of the regular season has offically been scrapped but NBA Comissioner David Stern said last week that the 2011-12 campaign would start in mid-December if a deal with players was reached.The latest collective barganing agreement, that players turned down on Monday, called for a 50-50 split of basketball related income between the owners and players and would have provided for a 72-game season to start on Dec. 15.The National Basketball Players Association also said it would no longer continue in collective bargaining and would dissolve the union to become a trade association in order to pursue legal action against the NBA.A shift from the negotiating table to the courts sets the stage for a potentially lengthy battle with the entire NBA season hanging in the balance.The NBA, which claims it lost $300 million last season with 22 of its 30 teams in the red, locked out players on July 1.Players, who received 57 percent of basketball income in the previous contract, also are at odds with the owners over rules governing contracts and free agency.