MOSCOW - Russian stocks plunged and Kuwait suspended trading as a slump in oil to below $55 a barrel roiled emerging markets and raised concern that Moscow will be forced to devalue ruble.

Russia's Micex Index fell as much as 17 percent and was 8.6 percent lower at 1:09 p.m. yesterday in Moscow after it reopened following a 30-minute trading suspension. A court in Kuwait ordered a shutdown as traders lobbied for support after a sixth day of declines. The MSCI Emerging Markets Index slid 2.9 percent to 518.22, adding to an 8.5 percent drop since Nov. 11.

"Alarm bells are ringing," said Tom Fallon, head of emerging-market research at La Francaise des Placements in Paris. "Weaker oil raises a number of issues for deterioration in terms of trade and budget assumptions which are now being seriously called into question."

The ruble has plunged 21 percent against the dollar in the past four months, even as the central bank sold 16 percent of its currency reserves in an attempt to arrest declines. Reserves dropped $9.2 billion last week to the lowest this year at $475.4 billion.

The ruble was 0.1 percent lower against the dollar at 27.5968 yesterday. The ruble will probably fall to 30 per dollar by the end of 2008, said Yurgens, who heads Moscow's Institute of Contemporary Development.

"Depreciating is almost inevitable," he said in a Bloomberg Television interview. "They will be depreciating the ruble."

The cost of contracts protecting against a Russian government default jumped to the highest in two weeks at 8.19 percent of the amount insured, up from 7.59 percent Wednesday, according to credit-default swap prices from CMA Datavision. Credit-default swaps, contracts conceived to protect bondholders against default, pay the buyer face value in exchange for the underlying securities or the cash equivalent should a company fail to adhere to its debt agreements.