* Housebuilders boosted by budget statement
* Supermarkets weaker after Sainsbury results
By Tricia Wright
LONDON, March 23 (Reuters) - Britain's top share index was flat after the UK budget held few surprises on Wednesday, with strength from miners offsetting falls from supermarkets as Sainsbury missed sales forecasts.
By 1332 GMT, the FTSE 100 was up 1.46 points at 5,764.17, retreating slightly from an intraday high of 5,802.44 reached before British finance minister George Osborne delivered his budget for the 2011/12 fiscal year to parliament.
"No major surprises so far in the budget. The BoE seems to have been let off of the need to get inflation back in hand this year, which may lead to a more doveish approach on interest rates," Mic Mills, head of electronic trading at ETX Capital, said.
"2010 growth has been cut back by more than expected but I'm not sure whether this is such a bad move or not, probably more realistic I think," he added.
On the second tier, UK housebuilders received some boost from the budget statement, aided by news that from this year's bank levy the government will fund a 250 million pound commitment to first-time buyers.
Redrow, Barratt Developments and Taylor Wimpey added 2 to 3.3 percent.
"A bit is happening with building firms in reaction (to the budget) but widely it's been a non-event," Joshua Raymond, market strategist at City Index, said.
"There wasn't really much speculation leading up to the budget considering that it's come so soon after the emergency budget, (so) we kind of knew the line that the government was going down," he said.
Kazakh miner Eurasian Natural Resources topped the bluechip leader board, up 3.5 percent after it met forecasts with full-year underlying profit that more than doubled.
This helped sentiment surrounding the sector as copper prices rose, and as mining executives said reconstruction in Japan after the earthquake would be bullish for metals.
Sainsbury, meanwhile, was the biggest FTSE 100 faller, off 6.1 percent as its fourth-quarter sales failed to meet expectations, stoking fears of a downturn in consumer spending.
Gloom on the outlook for grocery spending pushed peers Tesco and Morrison 2.1 percent and 1.8 percent lower.
Banks were also a drag on the index ahead of a crucial vote in the Portuguese parliament that could bring down the government, a reminder that the euro zone's debt crisis is far from resolved.
The Bank of England's Monetary Policy Committee remained divided on whether to raise interest rates this month and appeared no closer to tightening policy than they were in February. (Editing by Hans Peters)