According to sources close to the development, state-run Oil and Natural Gas Corporation (ONGC) and Oil India may even jointly bid for some blocks for which private parties have submitted expressions of interest (EoIs).

The last date for submitting bids for the 55 blocks on offer is May 2.

Sources indicate that at least 12-15 companies are likely to participate in the bidding, of which at least two to three are expected to be foreign firms.

“We understand that Cairn India is going to invest massively in the current round apart from the public sector. On the other hand, for those blocks where PSUs have not submitted EoIs, companies like ONGC and Oil India mainly, along with HPCL and BPRL, are likely to join hands for bidding," said an industry source.

The bidding process had two rounds, the first one included submission of expressions of interests, following which six companies had shown interest.

When asked about the possible participation of the Houston-based ConocoPhillips, Atanu Chakraborty, director- general of hydrocarbons, said, "A lot of Indian and foreign players are showing interest. We will be able to disclose it only after the bidding is over."

The date for submission of final bids was extended by a month from April 4 to May 2 after two overseas players showed interest.

For investors, this round is considered to be attractive as there will be a single licence for all forms of hydrocarbons, along with a simplified revenue-sharing model with marketing as well as pricing freedom.

During the current round, bidders have shown interest for around 60,000 sq km, as compared to 25,000 sq km during the previous rounds.

The new round of bidding for discovered small fields is also likely to kick off soon.

Under OALP, operators will have the flexibility to choose petroleum operations contracts (POCs) or reconnaissance contracts (RCs). While an RC will be for three years, those under a POC will have eight years for exploration and 20 years for development and production.