Workers at 2 Cameco mines authorize strike
* Workers vote 97 pct to give union strike mandate
* Key issue is retirement benefits, union says
* Shares up slightly to C$28.50 on the TSX
TORONTO, Oct 5 (Reuters) - Shares in Canadian uranium giant Cameco Corp (CCO.TO) were up slightly on Tuesday morning, despite a warning from the union at its Key Lake and McArthur Lake mines in Saskatchewan of possible strike action.
The United Steelworkers said late on Monday that Cameco's employees had voted in favor of giving the union strike mandate to back negotiations toward a new collective agreement.
Voting was held last week, with 97 percent of unionized employees saying they would strike if needed to support contract demands. The earliest possible date for a strike would be Oct. 22.
"We believe an agreement is possible without a strike but we need Cameco to help us," said union representative Randy Gratzka. "The parties need to be at the table talking."
The union and Cameco have met four times since August, with union members voting down two previous contract offers from the company.
The key issue for the around 525 unionized employees is better retirement benefits, the union said.
The previous labor contract expired at the end of 2009.
Shares in Cameco were slightly higher on Tuesday morning at C$28.50 on the Toronto Stock Exchange.
($1=$1.03 Canadian) (Reporting by Julie Gordon; editing by Peter Galloway)