May 21 (Reuters) - Blackstone-backed Spanish gambling company Cirsa's CIRSA.MC first-quarter core earnings rose about 8%, it said on Wednesday, citing stronger than expected performance from its retail and online betting businesses.

Cirsa reported earnings before interest, tax, depreciation and amortisation of €193.9 million ($225.3 million) for the quarter, up from €178.8 million in the same period last year.

($1 = 0.8605 euros)