By Mathieu Rosemain and Gwénaëlle Barzic

PARIS (Reuters) - French media giant Vivendi <VIV.PA> implied on Thursday that time was on its side in a spat with Mediaset <MS.MI> about a month after it backed out of a deal to buy the Italian broadcaster's pay-TV.

Vivendi, led by billionaire Vincent Bollore, said the binding share-swap agreement it signed in April with Mediaset could be void after Sept. 30, citing the initial regulatory calendar to obtain the go-ahead from the European Commission.

"The commission would not accept a formal filing while the parties were discussing their differences," Vivendi said in its statement. "In any event it is possible that the commission’s clearance might not be obtained before Sept. 30, on which date the contract would become void."

Vivendi and Mediaset signed an agreement in April, which would give the French group full control of Mediaset's pay-TV unit Premium and hand the two companies a 3.5 percent stake in each other.

But in July Vivendi backed out of the agreement saying it no longer wanted the whole pay-TV unit but only a 20 percent stake. It also said it intended to acquire around 15 percent of Mediaset shares in the next three years.

Mediaset had no immediate comment.

Separately, Vivendi said it would implement a 300 million euro ($338 million) cost-cutting plan to stem losses from the French channels of its pay-TV unit Canal Plus. The goal is to reach breakeven in 2018 for Canal Plus channels in France, it added.

Losses at Canal Plus' French business weighed on Vivendi's results. The group reported lower-than-expected quarterly core operating profit, partly due to increased losses at its French channels.

Earnings before interest, taxes and amortization (EBITA) for the three months that ended in June plummeted by 41.5 percent to 174 million euros, missing an average estimate in a Reuters poll of 247 million euros.

Total revenue over the period fell 1.9 percent from a year ago to 2.55 billion euros.

($1 = 0.8868 euros)

(Reporting by Mathieu Rosemain and Gwenaelle Barzic; additional reporting by Agnieszka Flak in Milan)