* Codelco seeks partners to value lithium assets in Chile
* Lithium exchange-traded fund up nearly 60 percent this year
* Firm says copper's rally key to Chile labour negotiations
* For Reuters coverage of LME Week, click on
LONDON, Oct 31 (Reuters) - More than 10 companies have expressed interest in partnering with Codelco, one of the world's largest copper producers, to exploit its lithium assets in Chile, the firm's chairman told Reuters.
The chairman, Oscar Landerretche, was speaking during LME Week, a gathering of the metal industry in London.
Lithium is a key component in rechargeable batteries that fuel electric vehicles, a segment of the auto industry expected to grow exponentially in coming years.
Companies with lithium assets are attracting huge investor interest, as can be seen in an exchange-traded fund comprised of lithium firms, up nearly 60 percent so far this year.
Lithium in Chile is found in brine deposits, which can take seven years or more to develop.
"Interest is in the lower double digits. Codelco is looking for partners for the process of valuing those lithium assets for their potential," Landerretche said, declining to give any names or say how large the deposit might be.
"But I would be cautious about overinterpretation because Codelco's lithium possessions are two salt lakes in the Atacama region and in very early stages of exploration and development."
Lithium-ion batteries use lithium carbonate or lithium hydroxide, but the industry typically talks in terms of lithium carbonate equivalent, which contains both.
Four producers dominate lithium processing: U.S.-listed FMC and Albemarle, China's Tianqi Lithium Corp and Chile's Sociedad Quimica Y Minera (SQM).
Analysts at UBS said earlier this year that they expect global sales of electric vehicles in 2025 to reach 14.2 million units, or 13.7 percent of the total, compared with under 1 million units, or less than 1 percent, in 2017.
Consultants Roskill estimate 785,000 tonnes of lithium carbonate equivalent a year will be needed by 2025, amounting to a 26,000-tonne shortfall from anticipated supply. That compares with 217,000 tonnes of demand versus 227,000 tonnes of supply this year.
Landerretche said copper's rally - up more than 20 percent so far this year at around $6,870 a tonne - would be important in Chilean labour contract negotiations.
"The challenge for companies is to keep the discipline of recent years," he said.
"The tightening of copper supply and the higher price is going to be more a determinant (of negotiations) than any regulation," he said, referring to the possibility of further labour reforms giving more power to the unions.
Chilean President Michelle Bachelet's tax and labour reforms received a lukewarm reception across the political spectrum.
Leftists complain the reforms are too timid, while the conservative opposition says they have stoked market uncertainty and crimped private investment.
Changes could come with the possible election of centre-right candidate Sebastian Pinera to the presidency next month.
State-owned Codelco's revenues last year amounted to about $11.62 billion, of which copper totalled $10.5 billion. The rest came from other products including molybdenum, gold and silver. (Reporting by Pratima Desai; Additional reporting by Fabian Cambero and Dave Sherwood in Santiago; Editing by Veronica Brown and Dale Hudson)