* BSE up 0.5 pct, NSE adds 0.27 pct
* FIIs buy for fifth straight session
MUMBAI, Jan 22 (Reuters) - Indian shares hit record highs for the third straight day on Thursday, led by blue-chips, tracking firm trends across the region and on optimism that the government will continue with the reform agenda.
The benchmark BSE index crossed the 29,000 mark for the first time ever on Thursday and hit an all-time high of 29,060.41, while the broader NSE index touched a record high of 8,772.70.
Asian shares held near eight-week highs on Thursday as investors bet on the likely size and scope of a bond-buying programme the European Central Bank is poised to unveil later in the day as it attempts to revive the flagging euro zone economy.
Investors have started rearranging portfolios on expectations of economic and fiscal reforms after the government said it would present the 2015/16 budget on Feb. 28.
Overseas investors bought Indian shares worth of 20.66 billion rupees ($334.7 million) on Wednesday, extending their buying streak for the fifth straight session, provisional exchange data showed.
"Positions are being build ahead of the budget. Overseas investors have put a lot of money in the last couple of days," said Deven Choksey, managing director of KR Choksey Securities.
"We remain bullish and valuations are still comfortable. I expect Nifty to trade between 8,400 and 9,000 for the time being," he said.
The BSE index gained 0.53 percent to 29,042.32, while the NSE index added 0.27 percent to 8,753.50.
Blue chips advanced, with Sun Pharmaceutical Industries rising 3.8 percent and Infosys Ltd adding 1.3 percent.
However, gains were capped as heavyweight Reliance Industries Ltd fell about 2 percent on reports that the government has toughens its stand in a $1 billion dispute over the Panna Mukta and Tapti oil and gas fields. ($1 = 61.7300 rupee) (Reporting by Indulal PM; Editing by Anand Basu)