New York regulators cleared the way Thursday for T. Rowe Price Group Inc. (TROW) to increase its position in power generator NRG Energy Inc. (NRG).

The state public service commission issued a ruling that allows the investment adviser to acquire up to 20% of the Princeton, N.J. power-plant operator. T. Rowe Price requested the ruling in light of a state regulation requiring commission approval for ownership of more than 10% of the stock in an electricity company.

T. Rowe Price in a filing said it seeks to increase its ownership of NRG shares as an investment and doesn't intend to use its position to change control of the company. As of March 31, T. Rowe Price was NRG's largest shareholder with a more than 8% stake, according to FactSet Research. T. Rowe Price holds authority and voting power over shares held by its clients, which include its own mutual funds and funds it advises.

NRG is currently the subject of a hostile bid by Exelon Corp (EXC). Shares of NRG were recently down 2.1% at $24.34 apiece.

-By Mark Peters, Dow Jones Newswires; 212-416-2457; mark.peters@dowjones.com