To HOCHTIEF Aktiengesellschaft, Essen, Germany

In accordance with our engagement, we performed an audit of selected information in the “Key Figures” section (pp. 11-12, 29, 30, 35, 36, 51, 52, 61) of the 2007 Sustainability Report of HOCHTIEF Aktiengesellschaft.

Management’s responsibility

The preparation of the 2007 Sustainability Report in accordance with the following criteria stated in the Sustainability Reporting Guidelines Vol. 3 of the Global Reporting Initiative (pp. 7 to 17)

materiality, sustainability context, completeness, balance, comparability, accuracy, timeliness, clarity and reliability

is the responsibility of the Executive Board of HOCHTIEF Aktiengesellschaft. This responsibility includes designing, implementing and maintaining an internal control system to the extent that this is relevant to the preparation of the Sustainability Report, selecting and applying appropriate methods for preparing the Sustainability Report and making estimates that are plausible under the given circumstances.

Auditor’s responsibility

Our responsibility is to express a limited assurance opinion based on our engagement on the key figures reported in the “Key Figures” section of the report for the German sites and units, on the worldwide key figures reported in this section on pp. 11, 12, 29 and 61, as well as on the targets for all sites and units reported in this section.

We conducted our engagement in accordance with the International Standard on Assurance Engagements (ISAE) 3000. For a limited assurance engagement, this standard requires that we comply with ethical requirements and plan and perform the engagement to obtain limited assurance about whether the key figures reported in the “Key Figures” section of the report for the German sites and units, the worldwide key figures reported in this section on pp. 11, 12, 29 and 61, and the targets for all sites and units reported in this section have been prepared, in all material respects, in accordance with the above-mentioned criteria stated in the Sustainability Reporting Guidelines Vol. 3 of the Global Reporting Initiative (pp. 7 to 17).

During our engagement, we gained evidence based on the assessment of risks and materiality to obtain limited assurance on the compliance of the selected information in the “Key Figures” section of the report with the specified criteria. We determined the nature and scope of our procedures, also on a sample basis, by using professional judgment to obtain limited assurance. Our engagement included the following procedures:

• Inspection of the documentation of the systems, processes and documents relating to sustainable management, including the job description of the CSR coordinator, the by-laws of the CSR Committee, the Code of Conduct as well as the directives on donations and sponsoring, crisis management, environmental protection and occupational safety, and procurement management.