Office of Fair Trading: revised guidance on the 'markets of insufficient importance' exception

Crucial, according to the guidance issued by the OFT, is the expected impact of the transaction on consumer welfare. This is established according to three main elements: market size, magnitude of competition lost by the merger, and the likely duration of that loss.
Market size is the sum of all suppliers' annual turnover in the UK in that affected market; where a merger results in several affected markets, the relevant figure will be the aggregate size of all such markets. In case of rapid market growth or decline, this will be taken into account in calculating future market size and importance. "Below the £10 million market size threshold, the OFT would generally consider the market to be of insufficient importance to justify a reference", subject to some caveats:
- very high market concentration and low entry prospects
- evidence of coordination
- the case raises novel issues
- "vulnerable" consumers would suffer a substantial proportion of the likely detriment.