The Post Rock and Lost Creek projects in Kansas and Missouri, respectively, have a combined operational capacity of 350MW.
The Ireland-based company said around $49m of the sale proceeds will be used to repay third party debt.
NTR CEO Rosheen McGuckian said: "Pattern Energy was the successful bidder following an extensive auction process which had garnered significant interest due to the outstanding quality of these operating wind assets.
"We are exceptionally pleased with the outcome and the value achieved for our shareholders."
The company announced its intention to sell the two wind assets in December, when it has appointed Marathon Capital as sale advisors.
Wind Capital has sold 500MW of wind projects over the past one year. It sold 150MW Osage wind farm in Oklahoma to TradeWind Energy in April 2014 for $60m.
In October, NTR acquired 14 wind energy projects in Northern Ireland through the purchase of KN Energy, as part of its strategy to invest in 150MW across the UK, Ireland and the Nordic region.
Image: The Lost Creek wind farm in Missouri. Photo: courtesy of NTR plc.
