GEORGETOWN, Guyana (AP) -- An Australian company announced Wednesday that it plans to open a large-scale gold mine in the South American country of Guyana this year.

Perth-based Troy Resources Limited said it plans to produce an initial 90,000 ounces (2.6 million grams) of gold annually.

Mining Minister Robert Persaud said the company expects to invest about $90 million to develop the mine and that it already has imported a $5 million grinding mill. The mine would open in Guyana's northwest Cuyuni region and would employ about 500 workers.

It would be the first major gold mine to open since Omai Gold Mines Limited, a consortium between Guyana's government and a Canadian company, ceased operations in 2005. The mine was once considered one of the largest open pit gold mines in the world, and it closed after waste overflowed into a nearby dam and caused an environmental disaster.

The government said that shortly after Troy Resources Limited opens its mine, Toronto-based Guyana Goldfields Inc. is scheduled to open a $205 million gold mine expected to produce an initial 200,000 ounces (5.7 million grams) of gold a year.

Gold is Guyana's main export and generated nearly $1 billion in revenue last year. However, Persaud said he expects that number to drop this year because of weaker gold prices.