The union representing 3,800 Air Canada customer service and sales agents says it is heading towards a possible strike on June 13 unless mediated talks result in a negotiated agreement.

The bargaining committee for the Canadian Auto Workers union local 2002 told members that strike votes will be held the week of May 16, as required by law.

That's less than a month ahead of a possible June deadline for a strike or lockout. The union is required to give 72-hours notice before a strike.

The federal Labour Department says that more than nine out of 10 disputes are resolved without strikes or lockouts.

A federal conciliator has been appointed to assist the parties at the union's request.

Under the conciliation process, any job action must first be subject to a cooling off period that includes 60 days of conciliation and 21 days of mediation.

The two sides plan to return to the bargaining table on Tuesday for seven days. Additional dates are scheduled from April 26 to May 6 and May 24 to June 13.

Unions often set dates for strike votes and strikes to increase pressure on employers to settle.

The union told members that the focus of the talks is to reach a settlement without a dispute.

But it added that bargaining continues to be challenging as it faces concession demands on a variety of subjects including pensions.

Air Canada (TSX:AC.B) sees these demands as productivity improvements, while the union characterizes them as concessions.

A spokeswoman for the carrier said it won't comment on the wide range of topics that are under discussion during the bargaining process.

But Isabelle Arthur said it has a good foundation in place to achieve a settlement.

The country's largest airline achieved a tentative agreement with its 3,000 pilots.