TORONTO, June 9 -- Mediated talks aimed at ending a nearly 11-month-old strike at Vale's (VALE5.SA: Quote) Sudbury operations have been adjourned until June 19, but the two sides made progress during the talks and will continue to discuss certain issues in the interim, the mediator said.

The Brazilian company and the United Steelworkers union began their most recent round of talks on Friday under the supervision of a mediator appointed by the Ontario provincial government.

"Progress was made," mediator Kevin Burkett said in a statement about the talks, which were to end on Monday.

"However, the period of time set aside to complete the task of negotiating a renewal collective agreement was insufficient," he said.

"The parties have agreed to continue two-party negotiations on certain issues in the interim."

The company and union have agreed to a media blackout and would not comment.

The walkout began July 13 and has, combined with a parallel strike at Vale's smaller Voisey's Bay mine in Eastern Canada, affected about 10 percent of global nickel production and lesser amounts of copper and precious metals.

The Sudbury operations in mineral-rich northern Ontario have been running at partial capacity for months, using non-unionized workers and outside contractors.