Aug. 1 -- Australia's Albidon Ltd. has cut its 2011 nickel concentrate output forecast by 21 percent at Zambia's Munali mine due to lower-than-projected ore production and quality, it said on Friday.

Nickel concentrate production for the full year to December 2011 is estimated at 44,000 tonnes, down from a May forecast of 55,279 tonnes, Albidon said.

"The Munali operation has not delivered the ore quantities and quality as promised thus far," it said.

A structural fault around the south primary ventilation shaft of the mine in June resulted in three days of lost output amounting to 420 tonnes of concentrate, it said.

"As a result of lower-than-expected production in Q2 and subsequent events, the full year forecast has been revised."

Albidon was reviewing operations at Munali and would pay particular attention to the mining methods to improve ore production and feed grade to the process plant, it said.

The mine is 50 percent owned by China's Jinchuan Group.

Albidon, which halted operations in mid-2008 at the southern African country's only nickel mine following a fall in metals prices, resumed output early last year after Jinchuan Group took a shareholding and invested $37 million.