The NBA made another offer to its referees last Friday, but it was narrowly voted down by the union's executive board, sources told ESPN.com.

The offer was made at an undisclosed bargaining session in Philadelphia.

Sources indicate that the union's five-man board met Sunday in Washington to discuss the offer. They turned down the proposal in a 3-2 vote, which led to the announcement of lead negotiator Lamell McMorris's departure from the talks on Monday.

McMorris released a statement saying the negotiations with the league would be handled by general counsel Brian Lam and the executive board of the National Basketball Referees Association from now on.