It added that no agreement or arrangement for any transaction has yet been reached.
Financial newswire Bloomberg linked Pattern to suitors including Brookfield Asset Management, including the suggestion of merging the company with New York yieldco TerraForm Power.
Brookfield owns about 65% of TerraForm Power, Bloomberg added.
Canada-based Brookfield has also been named in reports of a takeover involving Indian OEM Suzlon.
Shares in Pattern rose 8% on 12 August amid takeover speculation, closing at a year-high $25.15 on the New York Stock Exchange.
On 13 August, Pattern confirmed the approach form third parties and a transaction "may or may not be agreed as a result of any such inquiries or discussions".
Pattern has a portfolio of 26 renewable energy projects with a combined operating capacity of about 4GW in the US, Canada and Japan.