Oct 5 (Reuters) - First Quantum Minerals Ltd said it has revised its deal with Franco-Nevada Corp for its flagship copper-gold Cobre Panama project in Central America after reviewing the costs.

Under the new precious-metal stream agreement with the Vancouver-based miner, royalty firm Franco-Nevada will have to pay an initial contribution of $330 million to $340 million to First Quantum in October.

First Quantum's chairman and chief executive, Philip Pascall, said the company is acting "to ensure that profitability and cash flow from our mining operations are maximized and protected in these volatile market conditions and sustained lower commodity prices and second, that cash outflows are limited to essential and economically attractive projects so that our balance sheet integrity is maintained."

The Canadian base metals miner acquired the project in Panama in a hostile takeover of rival Inmet Mining Corp for C$5.1 billion ($4.8 billion) in 2013.

First Quantum said it now estimates that the total project cost for the open-pit Panama mine, which is 35 percent complete, will be $5.95 billion, about 7 percent below earlier estimates.

The project, which has cost $2.62 billion to date, is scheduled for process commissioning and first concentrate production in late 2017, First Quantum said. It expects the mine to produce about 320,000 tonnes of copper, 100,000 ounces of gold and 1.8 million ounces of silver a year on completion.

Remaining costs for project completion will be met by $666 million from the Korea Panama Mining Corp, $1 billion payable by Franco-Nevada under the agreement and $1.663 billion by First Quantum.

Capital costs for the project were reduced with better construction efficiency and lower costs for equipment and bulk materials such as rebar and structural steel, First Quantum said.

(Reporting by Rachel Chitra in Bengaluru; Editing by Leslie Adler)