On Monday, the 11 said they were very disappointed European soccer's governing body had failed to recognise the urgency of the situation.
"As long as no realistic alternative scenarios are proposed, the EuroLeague concept will be - among others - the subject of the ongoing investigations of the clubs involved," they said.
The 11 clubs - Ajax Amsterdam , Feyenoord and PSV Eindhoven of the Netherlands, Anderlecht and Club Bruges of Belgium, Brondby and FC Copenhagen of Denmark, Portugal's Benfica and Sporting and Scottish sides Celtic and Rangers - saw UEFA reject their Euroleague concept for a second time last week.
All 11 are also disturbed that clubs from the five largest European leagues - in England, France, Germany, Italy and Spain - have dominated the Champions League and UEFA Cup, and are monopolising revenues from the tournaments and from TV.
Their idea was to pool resources into a league featuring the biggest clubs from their respective countries with promotion and relegation. The idea had the tacit approval of some Swedish clubs such as AIK Stockholm.
UEFA said it would open up discussion on the future formats for club competitions, taking the smaller nations' concerns into account. Its executive board released a set of wide-sweeping guidelines, billed the 10 Commandments, that it said would form the basis of future club competition in Europe.
However, the clubs said in a joint statement: "(The clubs) seriously doubt whether the 10 principles for European club football... are in their consequences compatible with European law."
They said they were disturbed with the abstract nature of the proposals and said the timeframe was too long.
Their response is to continue discussions with their domestic leagues and football associations.
"UEFA has shouldered a heavy responsibility... Instead of coming up with an alternative or any suggestions, UEFA sketched 10 principles that put extra restrictions to finding a possible solution," said Celtic chief executive Allan MacDonald.
Reuters
Eleven soccer clubs from five of Europe's smaller nations are to keep alive the prospect of a breakaway "Euroleague" in the face of UEFA's failure to address their concerns.
