UPDATE 2-Russia limits oil, mining share sales to foreigners

(Rewrites, adds Mechel placement proceeding, details on rules, televised comments from head regulator)

By Olga Popova

MOSCOW, July 9 (Reuters) - Russia laid down official limits on the sale to foreigners of shares in strategic and raw materials companies on Wednesday, giving new regulatory force to the government's grip on Russia's natural resources wealth.

The new ruling by the state markets regulator codifies what the Kremlin has long made clear: the government is loath to see more of Russia's strategic and extractive industries fall into the hands of outsiders.

Under the new rules, published on Wednesday and entering into effect in 10 days' time, companies engaged in geological exploration are subject to the tightest cap, and will be allowed to sell only 5 percent of their shares abroad.

"They have completely locked down the sector," Uralsib bank equity strategist Chris Weafer said.

Companies in strategic industries related to national security and defence may only list 25 percent.

For other companies, the new limit is 30 percent of shares for any company wishing to make a new placement, down from 35 percent.

The ruling would strongly encourage Russian companies to raise capital at home, supporting President Dmitry Medvedev's ambition to make Russia a major financial centre by 2020.