After four months of preparations for what has been a historically divisive process, Yale and its two largest unions began negotiations on contracts for nearly 4,000 Yale workers Wednesday afternoon.

The two sides began talks by discussing procedures with John Stepp, a labor-management consultant hired last fall to help Yale and locals 34 and 35 mend their often tenuous relationship. After about two hours, he suggested that the two sides break up and caucus separately to prepare the issues they will bring up for bargaining later this week.

Wednesday’s talks come after nearly four months of meetings with Stepp, part of what leaders from both sides have said they hope will be the beginning of a new era in labor-management relations. At Stepp’s suggestion, leaders from both sides decided to pursue a new strategy called interest-based bargaining in the hopes of avoiding the contentious processes of the past.

Negotiations between Yale and its unions, which represent clerical, technical, service and maintenance workers, have often led to high tensions, and seven of the last 10 contract renewals have led to strikes.

Stepp said he expected both sides today to continue discussions of procedures, including behavioral ground rules, with bargaining beginning on Friday. Local 34 President Laura Smith and Local 35 President Bob Proto said each side would present the issues they wanted to discuss during today’s meetings, though Stepp said he did not think they would have time for more than procedural discussions.

Stepp said he thought the talks had gone “very well” so far.

The contracts for locals 34 and 35 expired in January, but both sides agreed to extend the contracts through March 1. After that, the contracts can be renewed on a month to month basis, with either side required to provide 15 days notice if it does not wish to renew the contract the next month.

Leaders on both sides have said they expect that the process will go slowly since they are using a new type of bargaining, and that bargaining will last at least through March. Stepp said Tuesday that he hoped to establish a target date during the early days of talks for completing negotiations, but that he could not give an estimate of when they would finish.

University leaders have said they do not expect wage and benefit issues to be major sources of contention this year. But both sides continue to disagree over the role of two groups trying to form recognized unions, graduate students and workers at Yale-New Haven Hospital. University officials have said the organizing efforts of the two groups should not affect this year’s negotiations with locals 34 and 35, but union leaders have said recognition for the graduate students and hospital workers is one of their objectives.