Reliance Industries Ltd has cut the gas reserves in its D6 block, off India's east coast, to 3.4 trillion cubic feet (tcf) from the 10.3 tcf estimated in December 2006, an oil ministry statement said on Thursday.
BP Plc is a co-operator with 30 percent stake while Canada's Niko Resources owns a 10 percent share in the block.
Niko Resources estimates that total proved plus probable reserves at the block had decreased to 1.93 trillion cubic feet as of March 31.