TORONTO -- A tentative deal has been reached between the Toronto Zoo and its workers, avoiding a strike or lockout ahead of a much-anticipated giant panda exhibit opening next month.

The zoo and CUPE Local 1600 -- representing more than 400 staff -- were faced with a midnight strike deadline Friday but chose to continue bargaining. An agreement was reached shortly after 2 a.m.

CUPE says details will not be disclosed until members have an opportunity to review the tentative deal and hold a ratification vote early next week.

The union had said cuts to bereavement leave, changes to sick pay and benefits, and job security were among the key issues at the bargaining table

Employees covered by the agreement include zookeepers, horticulturalists, tradespeople, maintenance, administration and public relations staff, concession and ride operators.

A strike or lockout at the zoo would have jeopardized the May 18 unveiling of an exhibit starring two giant pandas on loan from China.

The pandas -- five-year-old Er Shun and her prospective mate, four-year-old Da Mao -- arrived in Canada in March on a special flight from China.

Once the pandas complete their five-year stay in Toronto they will head to the Calgary Zoo, which has announced a major redesign that will cater to the new visitors.

The Calgary Zoo is hoping for a repeat of its last giant panda visit in 1988, when attendance almost doubled.

The zoo also plans to eventually house Japanese snow monkeys, seals and to bring back polar bears, which haven't been exhibited there since the last one, Misty, died in 1999.