The Russian ruble weakened to a record low in early trading on Monday following a drop in oil prices. The ruble hit 51.85 against the dollar in the first minutes of trading on the Moscow exchange, easing substantially beyond a psychologically important level of 50. This takes the ruble’s year-to-date loss compared with the U.S. currency to more than 36%. Against the euro, the ruble depreciated to 64.55 after Brent crude prices slid below $69 a barrel for the first time since May 2010. The ruble is widely expected to remain under pressure in December because of unfavorable conditions in commodity markets as well as hefty debt repayments. According to central bank data, Russian banks and companies have to reimburse around $30 billion in foreign debt by the end of the year. -Write to Andrey Ostroukh at [email protected]