Austrian property group Immofinanz signed a contract to sell its logistics portfolio to U.S. private equity group Blackstone, the company said on Monday as it switches focus to its retail and office business in western Europe.

The Austrian firm, whose results have been weighed down by its exposure to Russia, said in August it would concentrate on office and retail properties and sell its 1 million-square-metre logistics portfolio.

The deal with Blackstone covers all 36 of Immofinanz's logistics sites, 24 of which are in Germany. The remainder are in Hungary, Romania, Poland, Slovakia and Russia, Immofinanz said.

Blackstone will fold those sites into its European logistics unit Logicor and buy three development projects - one being built in Germany and two in Romania, Immofinanz added.

"The liquid funds released by the transaction will be invested in the expansion of our German portfolio, which will grow to nearly 200,000 sq metres of rentable space and up to approx. 40 million euros of rental income per year by mid-2018," Immofinanz Chief Executive Oliver Schumy said in a statement.

Immofinanz did not give an exact value of the deal.

The company said the deal was expected to close in the first quarter of next year, when the final purchase price would be set, adding: "The purchase price is determined by the property value of approx. 536 million euros, less construction costs of approx. 28 million euros for the three development projects."