The Indian equity benchmarks extended gains in noon deals on the back of buying interest in ICICI Bank, Infosys, Hindustan Unilever, Maruti Suzuki, Kotak Mahindra Bank and Larsen & Toubro. The Sensex rose as much as 522 points and Nifty 50 index reclaimed its important psychological level of 16,350. The market sentiment got a boost after the government decided to cut excise on petrol and diesel and also lowered custom duty on iron, steel and plastic products in a move to combat rising inflation, analysts said.