* Reconciliation talks fail
* Court case to start next week
LUSAKA, March 16 (Reuters) - Talks between Canada's First Quantum Minerals and labour unions for better conditions of service at its flagship Zambian copper mine have collapsed, prompting the two parties to take the matter to court, a union official said on Friday.
First Quantum agreed to a 15 percent pay rise with workers at the Kansanshi mine this month, but the two sides had differed over how long the agreement should stay in place.
Workers at the Kansanshi, Zambia's largest copper mine, which produced 231,000 tonnes of the red metal in 2010, downed tools but went back to work following appeals by officials from their union and management who held reconciliation talks.
"The talks didn't yield anything so the matter will be going to the industrial relations court next week," Mine Workers Union of Zambia acting president Charles Mukuka told Reuters.
Labour unions are demanding that the agreement should not last for more than 12 months but First Quantum wants it to run for two years, he said.
Glencore International Plc's Mopani Copper Mines in Zambia agreed a 17 percent pay rise with unions in February, almost triple the rate of inflation.
Konkola Copper Mines, part of London-listed Vedanta Resources Plc, awarded a similar pay increase to its workers in January.