The NFL's labor negotiations resumed Monday with the league and the players' union still close to $800 million per year apart on the central economic issue of how to divide the sport's revenue, according to sources familiar with the deliberations.If there is to be a settlement this week, it probably would have to involve a tradeoff between the two sides on the revenue split under a salary cap system and another key issue: whether a federal court judge in Minneapolis would continue to oversee the sport's labor deal, said sources from throughout the sport, who spoke on the condition of anonymity because the discussions are at a sensitive stage.A settlement, if it is to be completed by the new bargaining deadline Friday, also would be likely to include an 18game regular season that would be accompanied by reductions in offseason workouts and perhaps other concessions to the players, and a version of a rookie wage scale less restrictive than the NFL originally sought, the sources said.