NEW YORK (AP) — NHL owners and players are back at the bargaining table after a one-day break.

Negotiations began Sunday afternoon at the NHL office in Manhattan. Talks took place for four straight days earlier this week before heated discussions ended the run Friday night.

The sides were in contact Saturday, leading to an informal lunch in the afternoon. The decision to formally meet again came Sunday morning.

A few hours into Friday’s session, negotiations soured over the core economic differences that separate the sides and threaten the season completely.

The lockout is in its 57th day and has already caused the NHL to call off 327 regular-season games, including the New Year’s Day Winter Classic. A lockout wiped out the entire 2004-05 season.