The Commission, the executive arm of the 27 EU countries, reviews major corporate mergers and acquisitions to ensure they do not hurt fair competition in the market. It has the power to block deals or to demand concessions, such as the sale of business parts.
Here is a glance at some of the major decisions made by the Commission's competition authority:
—The same year, it allowed the carve-up of ABN Amro NV — the largest takeover in banking history — by a consortium led by RBS PLC and including Belgium's Fortis SA and Spain's Santander, with Bank of America as a side-player. The deal turned out to be a disaster for all the acquiring banks when the financial crisis struck just months later.
—In December, the Commission approved the merger between commodities trader Glencore and Xstrata, a major mining group, but only on the condition that it sell its stake in Nyrstar NV of Belgium, the world's largest zinc producer.