The rupee weakened for the fifth straight session against the dollar, today, and the domestic stock markets also ended lower. At the forex market, the rupee depreciated 17 paise, to a 39-month closing low of 68.73 against the dollar. During the session, the rupee had slipped to an all-time intra-day low of 68.86 against the US currency. Continued foreign fund outflows, a stronger dollar overseas and rising bond yields in the US dragged down the rupee. The stock markets snapped two days of gains, as the Sensex at the Bombay Stock Exchange declined 192 points, or 0.7 percent, to close at 25,860.The Nifty at the National Stock Exchange dropped 68 points, to 7,966. Other key Asian markets in Japan, China, Hong Kong, South Korea and Singapore ended mixed and Brent crude oil futures rose just 3 cents, at 48.98 dollars a barrel.