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A sister company to Toyota Motor Corp secured a lithium supply deal in Argentina on Wednesday that could help the world's largest automaker keep its lead in gasoline-electric hybrid cars.

The deal sent shares in the lithium project's owner and operator, Australian-listed Orocobre Ltd, soaring almost 50 percent to an all-time high.

Lithium, a highly reactive and versatile metal, is expected to be in increasing demand as carmakers choose costly but more efficient lithium-ion batteries to power hybrid and electric vehicles.

"When it comes to mass production of hybrids, the main hurdle has been a shortage of batteries," said Yoshihiko Tabei, chief analyst at Kazaka Securities. "Toyota is taking a step on its own to secure the materials it needs to ensure stable production."

Toyota Tsusho Corp, a trading house and key Toyota supplier 22 percent-owned by the automaker, said it would jointly develop a new lithium project in Argentina with Orocobre.

The Salar de Olaroz project in Argentina is estimated to cost around $80-$100 million, with the final figure to be determined after a feasibility study, Orocobre spokesman Paul Ryan said, adding the study should be complete by end-September.

"As environmentally friendly electric car demand continues to grow, Toyota Motor will have the opportunity to become a cornerstone offtake customer," Orocobre said in a statement.

Toyota uses nickel-metal-hydride batteries for the current Prius hybrid but has decided on lithium-ion batteries for future plug-in models.

Concerns about carbon emissions and their impact on climate change plus high and volatile oil prices are increasing the popularity of hybrid and electric vehicles despite their higher costs.

Toyota aims to double its global output of gas-electric hybrid cars to 1 million units in 2011, as it fights to stay in the lead in the growing market for low-emission cars, the Nikkei business reported this month.

Orocobre went public in December 2007 and now has a current market capitalization of nearly A$150 million.

Managing Director Richard Seville said the lithium market had been growing at a compound annual growth rate of about 7 percent between 1997 and 2007, before the global financial crisis, thanks largely to demand from consumer electronics makers.

"That growth will continue, but on top of that we have the step change in demand with a new application which is in large format batteries for use in electrical vehicles," Seville told Reuters.

Houston-based James Calaway, non-executive chairman, and his family members hold an 11 percent stake in Orocombre, while other board members own a further 15-20 percent, Seville said.

Subject to the finalization of the terms, Toyota Tsusho will acquire a 25 percent equity interest in the joint venture while Orocobre will continue to own the remaining 75 percent of the project and will operate the venture.

The Japanese government-affiliated Japan Oil, Gas and Metals National Corp s looking to take a part of Toyota Tsuho's 25 percent stake, as part of Japan's efforts to secure stable sources of rare metals, government officials said.

"Rare metals are essential not just for the high-tech sector but for Japan's manufacturing industry overall," said Hiroshi Kuwayama, a deputy director at Japan's Agency for Natural Resources and Energy.

"With other countries, such as China, investing in mines around the world, we want to be more aggressive to support the private sector in securing stable supplies."

Boliva has around 50 percent of the world's lithium reserves, but does not yet mine the metal, while Chile, China and Brazil also hold big reserves.