The Nifty PSU Bank index rises as much as 4.5 pct, the best performing sector on the NSE index.
Index posts biggest intraday pct gain since July 10.
India government may announce later in the day a plan to inject capital into public sector banks - local media reports.
State Bank of India, up 3.3 pct, was among top percentage gainers on the NSE index.
Punjab National Bank, Bank of India and IDBI Bank rose 6 pct, 4.5 pct and 4.7 pct, respectively.
