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May 6 (Reuters) - Supermarket group Ahold Delhaize AD.AS reported a first-quarter core profit above market expectations on Wednesday, as continued U.S. strength offset the negative impact from exchanging dollars to euros.

The group, which operates the Stop & Shop, Giant, Food Lion and Hannaford chains in the U.S. and the Albert Heijn and Delhaize chains in the Netherlands and Belgium, said its underlying operating income rose 0.7% to 896 million euros ($1.05 billion).

That was above the 858 million euros expected on average by analysts polled by the company.

At constant currency exchange rates, the core earnings rose 8.1% compared to last year, Ahold Delhaize said.

The group joins several other European firms that have been hit by unfavourable currency exchange rates, as translating the weak U.S. dollar to euros reduces reported results.

Ahold Delhaize's first-quarter sales rose 2% at constant exchange rates, but fell 4.3% on a reported basis, as a stronger euro weighed on its U.S.-heavy business.

($1 = 0.8524 euros)