(Corrects to show parliament, not firms, informed on delays)
NEW DELHI (Reuters) - Energy firms that have invested more than $12 billion have been hit by delays on required approvals for 52 exploration blocks, some awarded as far back as 1999, Oil Minister S. Jaipal Reddy said in a written response to parliament.
Approvals have been delayed due to defence, environment and maritime boundary issues, Reddy said.
Of the blocks awaiting approvals, 22 belong to Oil and Natural Gas Corp., 15 to Reliance Industries, five to BHP Billiton, three to Cairn Energy India and two to Australia's Santos Ltd.
British firms BG Group, BP and Italy's ENI own one each.
Reddy said clearances for larger areas from which these blocks are carved out are obtained from concerned ministries before auctioning them.
Contractors then need approvals from the defence, environment and forest, and foreign ministries as well as the relevant state governments to start or continue exploration or production work.
The firms have invested $12.4 billion for exploration and development activities in the blocks, Reddy told lawmakers.
The world's fourth biggest oil importer, India wants to tap domestic supply to cut its ballooning import bill and widening fiscal deficit.
Its crude oil import bill surged 48 percent to 6.72 trillion rupees in the year to March due to rising global oil prices, declining rupee and expanding refining capacity.
The economy is growing at its slowest pace in nearly a decade and policy paralysis has stalled major reforms including those on fuel pricing, denting global investors' confidence in the Indian oil sector.
In 2010, Brazil's Petrobras and Norway's Statoil exited from a block operated by ONGC in the hydrocarbon-rich Krishna Godavari Basin off India's east coast.
India, which imports about 80 percent of its oil needs, has awarded 249 blocks under nine licensing rounds since 1999. Oil and gas discoveries have been made in 38 blocks.
(Reporting by Nidhi Verma; editing by Jason Neely)