NEW YORK — In a move engineered by a federal mediator, Gary Bettman and Donald Fehr met Saturday for a daylong bargaining session, the first face-to-face talks between the NHL and the players’ union since negotiations broke down Thursday.

The session had an all-or-nothing feel to it. It took place as players completed a vote on whether to authorize Fehr to dissolve the union if negotiations stalled. If Fehr were to exercise that option, it would very likely end the bargaining and send the proceedings to court.