It was tasked with ensuring healthy competition between companies in the UK for the ultimate benefit of consumers and the economy.

The Enterprise Act 2002 gave the Competition Commission wider powers and greater independence than the MMC had previously, so that it could make decisions on inquiries rather than giving recommendations to Government, and was also responsible for taking appropriate actions and measures (known as remedies) following inquiries which had identified competition problems.

The Government was still able to intervene on mergers that involve a specified public interest criterion such as media plurality, national security and financial stability.

[3][4] The Competition Commission (CC) was an independent public body which conducts in-depth inquiries into mergers, markets and the regulation of the major regulated industries, ensuring healthy competition between companies in the UK for the benefit of companies, customers and the economy.

Under the Enterprise Act 2002 (the Enterprise Act), the OFT could review mergers to investigate whether there was a realistic prospect that they would lead to a substantial lessening of competition (SLC), unless it obtained undertakings from the merging parties to address its concerns or the market was of insufficient importance.

Companies regulated under the gas, electricity, water and sewerage, postal services, railways or airports legislation generally had a formal instrument (a licence) setting out the terms of their operation.

The CC had an appeal function following decisions by the Gas and Electricity Markets Authority to modify certain energy codes under the Energy Act 2004 and in relation to price control decisions by Ofcom, following a reference by the Competition Appeal Tribunal (CAT) under the Communications Act 2003.