Competition Commission checks out the bottom line...Mobile phone charges are to come under the spotlight as the Competition Commission has decided to extend its investigation into the cost of phone calls between the UK's mobile networks to include all the operators' consumer pricing models. In a statement issued today, the Commission outlined the areas it will be covering in its investigation and said the net will be spread further than just termination charges - the subject of an earlier probe. Oftel believed the charges between the networks were too high - as much as 39 pence per a call - and began looking into the matter last year. The telecommunications watchdog handed the investigation over to the Commission in January after the four operators protested at the probe. The Commission will now investigate the level of competition in the market, plus the operators' overall pricing structures. A spokeswoman from the Commission said: "Our remit was to look at the termination charges of calls between networks, but we can't look at these in isolation as they impact on other charges." A spokeswoman from Orange said the Commission's new remit is in line with its wishes and a spokesman from Vodafone said the company will continue to participate fully in the process. However, BT Cellnet is not in favour of any review and said: "BT Cellnet has rejected the proposed modification to its licence regarding call termination rates. The UK has a vigorous, highly competitive market where customers enjoy a high level of choice. We do not believe it is in the customer's interest to impose a crude and compulsory call termination rate." The Commission has given the operators 10 days to voice further concerns then it intends to decide the matter before the end of July this year.