Ad-hoc announcement in accordance with Art. 15 WpHG: Share Buyback PSI AG Executive Board Decides on Continuation of Share Buyback

Berlin, 4 May 2009 – The Executive Board of PSI AG (ISIN DE0006968225) decided on 4 May 2009 to buy back up to 800,000 of its own shares (this corresponds to approx. 6.7 percent of the capital stock) through the stock exchange.

The decision follows the authorization of the Annual General Meeting on 25 April 2008 for the buyback of own shares of up to 10 % of the capital stock. The buyback program is limited to 30 September 2009. The shares may be used for all the purposes authorized in the General Meeting. This includes in particular the use as acquisition funds for the upcoming corporate acquisitions. The purchase price per share may not exceed the closing price per share of the Xetra trading system on the preceding day by more than 10%, nor may it be less than 20% below the same price.

PSI AG develops and integrates individual solutions, on the basis of its own software, for the management of energy networks (electricity, gas, oil, water, heat), cross-company production management (metals, mechanical engineering, automotive, logistics) and infrastructure management for telecommunications, transport and safety. PSI was founded in 1969 and currently employs more than 1,100 persons in the group.