"After sharing of active and backhaul infrastructure is accepted, the next step will be sharing of scarce resource - spectrum," TRAI chairman Nripendra Misra told reporters.

The new policy may come into effect in the next two years, he said, adding that TRAI would consider giving incentives to telecom companies for their performance in rural areas.

"In the next 2-3 days, TRAI will come out with a consulation paper, which will look into various issues such as mergers and acquisitions, substantative equity holding in telecom companies, use of two technologies by a telecom company and roll out obligations," he said.

Misra said the telecom regulator would also look how to give incentives to telecom companies for rural performance in the roll out obligations. The next phase of growth in telecom sector would come from rural areas, he added.

Misra said ''affordability'' has pushed the growth in this segment, which is likely to continue for the coming years and the government has now fixed a target of achieving 250 million subscribers by the end of this year and 500 million by 2010.