Benchmark Sensex ended below the key 36,000-mark in see-saw trade today as investors remained on the sidelines ahead of the Budget. Bombay Stock Exchange dropped 68.71 points to close at 35,965. The broader Nifty too suffered losses but managed to end above the 11,000-level and closed at 11,028.Caution prevailed for the second session in a row as participants were unwilling to expand their portfolios and looked to the Budget for further cues, brokers said.