Integrys Energy Services Inc, a unit of Integrys Energy Group Inc, said it agreed to sell its wholesale electric marketing and trading business to a unit of Australia's Macquarie Group Ltd.

Integrys, which did not disclose the financial terms of the deal, said in a statement the transaction is expected to reduce collateral support requirements by approximately $400 million.

The company did not immediately respond to a voice mail seeking comment.

The deal, to be completed in two steps, will be closed by the second quarter of 2010, Integrys said.

It said the transaction does not include or directly affect its retail electric or natural gas marketing business.

The sale to Macquarie Cook Power includes physical forwards, financial derivatives, capacity and transmission rights, with an annual average total gross volume in excess of 125 million megawatt-hours over the past 3 years. Separately, Macquarie Cook Power said the acquisition will almost double its customer base and scale of its existing power trading business, while strengthening its position across key North American power markets.

JP Morgan Securities was the financial adviser to Integrys Energy Group.

Shares of Integrys closed at $42.47 Thursday on the New York Stock Exchange. (Reporting by Krishna N. Das in Bangalore; Editing by Unnikrishnan Nair)