July 16 (Bloomberg) -- OZ Minerals Ltd., which operates the A$1.2 billion ($1.06 billion) Prominent Hill mine in Australia, said second-quarter copper output rose 4 percent and boosted its full-year gold production forecast.

Copper output was 28,236 metric tons, Melbourne-based OZ Minerals said today in a statement. That compares with 27,159 tons in the year earlier period. Gold output more than doubled.

OZ Minerals yesterday approved a A$135 million underground development at Prominent Hill after the Australian government excluded base metals mines from its new profits tax. The price of copper in London averaged 51 percent higher than the same period a year ago, it said.

"The medium-term outlook for the copper market is very good," Chief Executive Officer Terry Burgess said on a conference call. "The concentrates market continues to be very tight."

OZ Minerals, which this month acquired a 19 percent stake in Sandfire Resources NL for A$100 million, rose 1.4 percent to A$1.13 at the 4:10 p.m. Sydney time close on the Australian stock exchange. The stock has dropped 4.2 percent this year.

Gold production was 49,249 ounces, the company said. That compares with last year's 18,351 ounces. The company raised its full-year gold output forecast to between 140,000 ounces and 150,000 ounces, from 110,000 to 120,000 ounces.

Production of copper during the second half of the year will be lower than the first six months because of expected lower copper grades, the company said. It reiterated its full- year output forecast of 100,000 tons to 110,000 tons.