SANTIAGO, June 14 (Reuters) - Workers at Chile's Collahuasi have voted to approve a new, early contract proposal, the union told Reuters on Friday, calming fears of labor unrest at the world's third-largest copper deposit. Nearly 90 percent of the 1,090 workers who voted cast their ballots in favor of the deal to replace a contract due to expire in April 2014. Under the new four-year contract, workers will receive a 3.5 percent salary increase, a roughly $31,900 bonus and a loan worth $6,000. Union leaders are due to sign the contract on Friday. The anticipated contract deal mirrors a recent trend in top copper producer Chile, where miners have increasingly sought to reach early, sweetened deals with their unions to lessen the risk of strikes. Production at Collahuasi, owned by Anglo American Plc , Glencore Xstrata Plc and a group of Japanese companies led by Mitsui & Co, is expected to recover this year after a tough 2012. Last year, the mine's output nosedived to 282,100 tonnes from 453,300 tonnes in 2011. Two key mines reached early contract deals in recent months, soothing some fears of strikes. World No. 1 copper producer Escondida settled early with its union in January, while state copper firm Codelco reached a fresh deal with workers at its Andina mine in October.