European leaders paid tribute on Wednesday to Austrian President Thomas Klestil, who has died aged 71, describing him as a "great European".

"He was a great European who played a major role in advancing the development of the European Union," European Commission chief Romano Prodi said in a letter to Austrian Chancellor Wolfgang Schuessel.

He said he extended the "heartfelt condolences" of both himself and the rest of the EU executive.

Klestil died late Tuesday in a Viennese hospital following a heart attack, just two days before his second six-year term as president was due to end.

European Parliament president Pat Cox also send his condolences to Klestil's wife and family, and to the government and people of Austria.

"I recall and pay tribute to his deep sense of service to the Austrian people and the calm and effective diplomacy which he so unfailingly displayed over many years," the Irish head of the EU assembly said in a statement.