Sagittarius Mines, a unit of mining giant Glencore Xstrata, is planning to slim down budget for its $5.9bn Tampakan Copper-Gold Project in Philippines and will cut nearly 920 jobs at the mine amid several key challenges.

The company will be taking a new approach to tackle substantial development challenges such as a ban on open-pit mining operations in South Cotabato province.

Other challenges faced by the mine include the definition of the pathways to project approvals from all levels of government and the gaining of approval and the resettlement of impacted communities.

Sagittarius Mines spokesman John Arnaldo told Reuters that the company cannot determine when commercial production could commence at the mine until these challenges are resolved.

Sagittarius Mines executive vice-president Justin Hillier said that the shareholders have considered a range of options presented by the management, and have approved a revised approach for the project, with focus on enhancing collaboration with National Government partners and other stakeholders, to resolve problems.

"This plan will reduce current activity levels and expenditure on the Project, and regrettably this reduced activity and expenditure will result in staff downsizing and a reduction in the utilization of contractors," Hillier added.