The investment would form part of the equity of Adani Power, Neil King, a partner at 3i India Infrastructure Fund, said, but h declined to reveal the size of the stake.

Of the investment, $114 million came from 3i Infrastructure''s investment in its Indian sister fund, and the rest from 3i Group.

3i India Infrastructure had raised $500 million, its first fund in September, with $250 million coming from parent 3i Group and the balance coming from 3i Infrastructure Ltd.

Adani Power, a part of the Adani group, is developing an independent 2640 MW imported coal-based thermal power plant in Gujarat. The group has interests in port, power generation, gas distribution, oil and gas exploration, and logistics.

"We made an investment in a port in Mundra about 18 months ago with Adani, and the relationship expanded into other things," King said, adding, that Adani has plans for other power plant projects.

"We have no plans at the moment, but if Adani''s plans come to fruition there will be discussions about further investment." King added.

3i Group established the Indian fund along with India Infrastructure Finance Co. Ltd. in April. Mumbai-based 3i India Infrastructure has invested $325 million in India since 2005, with investments ranging from real estate, media and automotive companies to infrastructure projects in power and ports.