• Number of games would be reduced from 12 to nine a year • European Club Association yet to agree terms with Fifa

A dispute between Europe's most powerful clubs and Fifa over international fixtures has escalated. The European Club Association agreed a new deal with Uefa at its general assembly in Warsaw over insurance for players on international duty and dates for friendlies, but are unhappy at Fifa's approach to negotiations.

The agreement between the ECA, which represents 201 clubs, over the international calendar – which will lead to the unpopular August international friendly date being axed – still has to be ratified by Fifa. The power struggle has major ramifications for the future of the game, with the clubs nursing long-held grievances about providing the players for Fifa's World Cup and what they see as the encroachment of international football on the calendar.

"It is not our will to go against Fifa," said the ECA chairman, Karl-Heinz Rummenigge. "But our request for transparency and democracy has to be accepted."

While Rummenigge praised the Uefa president, Michel Platini, for his approach to the negotiations, he pointedly criticised Fifa's president, Sepp Blatter. "This is once more a proof that in the European football family solutions can be found in a co-operative and fair way," he said.

"While an agreement has been reached with Uefa, the situation remains unsatisfactory in relation to Fifa. Unfortunately discussions with the Fifa president have failed to lead to a satisfactory outcome which takes account of the clubs' demands."

Fifa immediately responded with its own statement, saying it was "surprised" by the ECA's stance. It said Rummenigge and the ECA's general secretary, Michele Centenaro, had been invited to attend a meeting of a new working group to discuss the international calendar on 5 March but had refused to attend."ECA representatives have previously declined attendance to other Fifa committee meetings, making it very difficult for progress to be made in discussions with the European clubs," said Fifa. It added: "Finally, Fifa would like to recall that the international dates and the international match calendar have to be applied on a worldwide basis and that this calendar is ultimately regulated by Fifa, as football's world governing body."

The successful negotiations with Uefa head off any immediate threat of a breakaway alternative to the Champions League, which had been privately mooted by some of the more bullish voices within the ECA. Under the new agreement with Uefa over the use of their players by national teams, European clubs will share a "substantially increased" sum over and above the 55m euros previously agreed for Euro 2012.

There will be "a further increase" for the Euro 2016 finals in France, with the new amounts for both tournaments to be announced at the Uefa Congress in Istanbul next month. Uefa also said it will cover players injured on international duty starting with this June's Euros in Poland and Ukraine.

Major changes have also been agreed, subject to Fifa's approval, to the international calendar. Last year, the ECA proposed drastically reorganising the international calendar into six double headers for each two-year international tournament cycle, but a "compromise solution" of nine double-headers starting in 2015 was agreed. There will be no single dates for friendlies with the unpopular August friendly dropped from the calendar, probably from 2014.