NRG Energy Inc . (NYSE: NRG) detailed the results of its previously announced offer to purchase up to $400 million, in aggregate principal amount, of outstanding senior notes, the company said Feb. 10.

Senior notes, at 8.50%, due 2019 and senior notes, at 7.625%, due the same year had a tender offer which expired Feb. 7, the company said.

Gross tendered amounts, of $308,520,000 in 8.50% notes and $191,792,000 of 7.625% notes, respectively, were noted by the company.

The offer expired Feb. 7, the company said.

NRG is dually based in Princeton, N.J. and Houston. It has assets in oil and gas nationwide, and owns and operates a major power generation portfolio.