The bid documents, data collection and seismic survey have been completed for CBM and the ministry has to get the concurrence of Madhya Pradesh, Bihar and Gujarat governments for awarding the blocks in their states, petroleum ministry sources said.

The ministry, they said, was planning to invite bids for about nine CBM blocks during the current year and acceptance of West Bengal had already been received.

These three states - Gujarat, Madhya Pradesh and Bihar - have good reserves that could be awarded under CBM, but certain demands made by these states were causing delay in inviting bids, the sources said.

While the ministry is planning to put on bid one CBM block in West Bengal, some five to six blocks in the other states could be awarded, the sources said.

Declining to give the conditions put by the three states, the sources said the ministry had planned to hold road shows in July this year in case of an early clearance.

They, however, said that bids for CBM was likely to be invited during October-November this year along with the second round of New Exploraiton and Licensing Policy (NELP).

As per the proposed terms and conditions of the CBM bids, sources said, the size of the blocks could be in the range of 200 to 500 square km with reserves of about 2.5 trillion cubic feet.

The bid evaluation criteria would be based on the technical competence and CBM/oil and gas experience of bidder/consortium besides the financial strength of the company/consortium, the sources said.

Coal bearing formations are lower Gondwana and North eastern terrotories, they said, adding that bulk of the coal resources within the 1000 metre depth are within the Godwana sequence.

The eastern basins of the damodar valley belt like the Raniganh, Jharia, East and West Bokaro, Stapura basin and the central part of South Rewa basin in Central India are considered to be the most potential target areas for exploitation of CBM, the sources said.

While the estimated reserves for the Raniganj is about six trillion cubic feet, Jharia has reserves of about 4.5 trillion cubic feet, they said.Sohagpur, East Bokaro and West Bokaro have estimated reserves of four, three and two trillion cubic feet respectively, the sources added.