The decision gives the 15 ITV contractors at least another three months under the existing regime, which they want preserved and independent programme makers want scrapped.
The OFT found that the existing system penalised independent programme makers and put other broadcasters at a disadvantage to Channel 3 licensees.
It proposed rule changes to allow independent producers to sell programmes directly to the ITV network. It also suggested outlawing long-term contracts that give broadcasters exclusive rights to programmes for up to 15 years.
The MMC inquiry was expected after the ITV companies and the Independent Television Commission lodged a formal request. Under the Broadcasting Act 1990 the MMC is obliged to investigate unless it considers the request frivolous or vexatious.
The MMC said it expected the investigation, the first under the Broadcasting Act, would take less than three months. The old networking regime will continue while it takes place.
John Woodward, chief executive of the independent producers' trade body Pact, said the investigation was a waste of time. 'We are confident the MMC is only going to reiterate what the OFT has already said,' he went on.
'It is a calculated attempt by the ITV companies to hoover up a whole range of programme rights in the interim three months.'
The ITC, the broadcasting regulator, is concerned that if independent producers sell direct to the network programmes will not be properly vetted. At present the Channel 3 companies are responsible for all programmes they sponsor, even if they are produced independently.
The Channel 3 companies attacked the OFT's findings, accusing the Director-General of Fair Trading, Sir Bryan Carsberg, of creating 'a charter for Rupert Murdoch' - whose BSkyB satellite channels are unaffected.Reuse content