Italian broadcaster Mediaset has taken legal action against French media conglomerate Vivendi for alleged breach of contract in a new twist in the ongoing tensions between the two European media giants over a pay-TV deal which has gone sour.

The concrete legal step follows a war of words between Vivendi CEO Arnaud de Puyfontaine and Mediaset chief executive Pier Silvio Berlusconi (pictured) ever since Vivendi in late July announced it was backing out of the deal.

Mediaset, which is controlled by former Prime Minister Silvio Berlusconi’s family, announced on Friday it has filed a suit asking a Milan court to enforce the sale to Vivendi of its Mediaset Premium pay-TV arm.

In a statement Mediaset said it is asking for damages estimated at 50 million euros ($56.6 million) per month for every month of delay starting from July 25.

In April the two companies had announced an agreement that would see Vivendi acquire a 100% stake in Mediaset Premium as part of a wider strategic alliance that included a 3.5% share swap.

But Vivendi announced last month it was seeking to pull out of its purchase of the loss-making pay-TV unit claiming that analysis by audit group Deloitte of Mediaset Premium revealed different numbers than those they had been provided by Mediaset and also an “unrealistic” business plan.

Mediaset shares tumbled in the ensuing war of words. Mediaset’s stock value has dropped 14% since the deal collapsed, according to a calculation by Italian financial daily Il Sole 24 Ore.

Mediaset in the statement said that if Vivendi does not honor the deal it risks losing 1.5 billion euros ($1.7 billion).

But at this stage Mediaset is not asking for those damages, indicating they are still seeking to negotiate.

“The damages sought concern purely the delay accumulated so far and possible further delays caused by inventive and dilatory proposals of different accords than the one in place,” the Mediaset statement said.

Mediaset’s legal action takes place just as its stock value picked up 2.75% last week because of rumours that it was starting to work out an alternative agreement behind the scenes with Vivendi that would keep their strategic alliance in place.

The key to seeing where the two companies really stand is expected to be Vivendi’s upcoming board meeting on August 25.