MUNICH/FRANKFURT (Reuters) -Private equity firm Warburg Pincus is nearing a deal to buy German software maker PSI Software in a deal worth more than 700 million euros ($813 million), two people familiar with the matter said.

The transaction would value PSI, a maker of software for energy networks, at 45 euros per share, the sources said, a premium of more than a third on Friday's closing price.

The deal is not finalised yet and details could still change, the people said.

PSI declined to comment.

Warburg Pincus was not immediately available for comment.

($1 = 0.8607 euros)

(Reporting by Alexander Huebner and Christoph Steitz; Editing by Ros Russell)