The Indian equity benchmarks extended gains and hit fresh four-month highs on Wednesday led by gains in Reliance Industries, NTPC, ICICI Bank, Larsen & Toubro, Hindustan Unilever and ITC amid stable cues from other Asian markets. The Sensex rose as much as 378 points to reclaim 60,000-mark for the first time since April and Nifty 50 index reclaimed its important psychological level of 17,900.