On 15 November 2007, the Office of Fair Trading (OFT) issued revised guidance concerning references to the Competition Commission (CC) that involve ‘markets of insufficient importance’. Following a public consultation, the merger guidance has been amended to reflect the consensus that the market size threshold for ‘markets of insufficient importance’ should be raised from £400,000 to £10 million. However, the OFT has discretion not to use the exemption even where the value of the market falls below the new threshold. References are still likely to be made to the CC where the merger is likely to have a significant impact on a market (e.g. where there is a high market concentration), there is increased risk of co-operation between competitors or a reference will result in important guidance to an industry.