Baja Mining Corp said its South Korean partners for the Boleo project in Mexico were unable to decide on the second stage of financing for the copper-cobalt-zinc project.

Baja said the South Korean consortium, which injected $90 million in the first phase of financing, was still evaluating if additional funds were necessary to complete the project.

The miner has extended the deadline for the consortium to complete its diligence for the second phase of financing to Sept. 15.

Baja has been struggling with cost overruns at its flagship project. Spending at Boleo is expected to be $246 million more than the $1.14 billion estimated in 2010 because of design changes and higher fuel and labor costs.

Baja shares were down 3 percent at 12.5 Canadian cents on Tuesday morning on the Toronto Stock Exchange.