Oil explorers sink on crude plunge, Russia worries

Reuters Market Eye - Shares in Oil and Natural Gas Corporation Ltd falls 3.4 pct, Essar Oil falls as much as 3.1 pct.

Oil prices plunge to a 5-1/2 year low after OPEC rules out cut in oil output.

Russia's central bank raises its key interest rate to halt a collapse in rouble, raising fears about global economy. Russia's economy has been hit by the fall in oil prices and Western sanctions

Essar Oil signed a key deal with Russia's Rosnet in Dec.

ONGC is already a stakeholder in the Rosneft-led Sakhalin-1 oil and gas project in Russia's Far East.

(Reporting by Dipika Lalwani)