STV, the Scottish commercial broadcaster, is preparing to hit back at ITV with a claim of up to £40 million, amid a row over advertising revenues that it says should have been sent by ITV north of the Border.

The likely lawsuit opens a second legal front between the broadcaster and the network and emerges a day after ITV said that it would sue STV for £38 million in a dispute about cash due for programmes made in London but not aired in Scotland after STV dropped shows such as The Bill.

The two have been arguing about advertising revenues for 18 months, after the Scottish company demanded the right to inspect the books of ITV’s advertising sales team. ITV sells advertising nationally and sends the Scottish portion of that money to STV.

However, with STV unsure whether it had received its correct entitlement of cash, its executives asked Deloitte. the accountants, to inspect ITV’s books under the terms of a network agreement intended to protect the rights of the small ITV companies.

In a statement, STV accused ITV of “preventing” Deloitte from “carrying out a full review of all revenue-related contracts”. STV said that it had been able to audit only 5 per cent of the contracts covering 2½ years of a six-year period, which it claimed had uncovered a “potential shortfall” of £2 million. This, it said, suggested a possible overall claim of up to £40 million.

ITV said that it would contest any counter-claim from STV, adding that there was no evidence of a £2 million shortfall. A spokesman for the London-based company said: “It is simply untrue and disingenuous to suggest that ITV has prevented STV’s independent auditor, Deloitte, from carrying out a review of contracts. We have been co-operative and supplied all documents relevant to the review which, in any case, we believe to be flawed.”

ITV, which has still to appoint a chief executive to succeed Michael Grade, owns 11 of the 15 regional licences that once made up the structure of the network. STV owns the two Scottish licences, while two other companies, UTV and Channel, control the remaining franchises in Northern Ireland and the Channel Islands.

The home of Taggart

STV has been broadcasting since 1957 and is based in Glasgow. STV North, which first aired in 1961, is based in Aberdeen and covers the largest area of any ITV licence

STV Productions makes the dramas Taggart and Rebus for ITV1 and factual programming such as Jack Osbourne: Adrenaline Junkie for ITV2. It also owns Ginger Productions, which was set up by Chris Evans

STV shares closed up 6.2 per cent, or 5½p, at 94p

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