LA PAZ (Reuters) – Bolivia’s government will not make a final decision on potential lithium mining tie-ups with private partners until December, six months behind its initial schedule, a senior official told state television on Friday.

The government is currently evaluating six companies to help mine the country’s untapped lithium riches. One or more could eventually be selected to partner with state-owned Yacimientos de Litios Bolivianos (YLB).

Alvaro Arnez, vice minister of high energy technologies, told the state broadcaster that the government now plans to have proposals ready for companies to consider by the end of October, with a final deal or deals in place by the end of December.

The government had previously planned to announce its final selection last month. It hopes private partners can help jumpstart lithium extraction in Bolivia’s sprawling salt flats, home to the world’s largest deposits of the white metal coveted by rechargeable battery makers.

Despite decades of attempts, Bolivia has yet to achieve any commercial lithium production. Demand for the ultra-light metal has surged in recent years.

This month, the government narrowed the final selection from eight to six suitors, after disqualifying American startup EnergyX and Argentine energy firm Tecpetrol.[L1N2XW01M]

Bolivia, one of the poorest countries in the Americas, faces steep challenges to meet its target of producing lithium-ion batteries locally by 2025.

A Reuters report last month highlighted the technological challenges, social resistance, legal obstacles and political scrambles undermining Bolivia’s extractions plans. [L2N2X906]

None of the short-listed firms have exploited lithium at a commercial scale before.

(Reporting by Daniel Ramos; Writing by Isabel Woodford; Editing by David Alire Garcia and David Gregorio)