Chilean state-owned miner Codelco has launched a bidding process for a $2.3 billion contract to supply fuel to the world's largest copper producer.

The contract includes fuel supply, transport, storage, internal distribution services, automatization and minor maintenance, among other services, for a five-year period beginning in May 2015.

"The main goal of the bidding process is to maintain Codelco's competiveness, favoring long-term contracts under conditions that encourage the participation of the largest number of bidders," Andres Alonso, Codelco's energy and water resources chief, said.

In 2009, the copper giant awarded two fuel contracts to Chile's Enex, as well as a third to Brazilian state-controlled energy giant Petrobras to supply its Salvador division, located in the Andes mountains 1,100 kilometers (680 miles) north of Santiago.

Companies or consortiums must make it through a pre-qualifying phase to become eligible to participate in the second and final stage of the bidding process.

Codelco expects to award the contract at the end of this year.