MADRID, June 25 (Reuters) - Spain's Volotea said on Tuesday it was teaming up with Abra, which owns Colombian airline Avianca and Brazil's GOL, to take over slots that IAG pledged to hand over in order to get approval for its merger with Air Europa.

The deal does not involve any changes to the shareholding structure, Volotea CEO Carlos Munoz said, adding that there was no cost involved for the joint venture partners.

Munoz told a news conference in Madrid that the deal sought to optimise the set of remedies with the integration of a long-haul and a short-haul network.

Abra CEO Adrian Neuhauser said the joint venture did not require authorisation from anti-trust authorities, since the two airline groups do not compete directly.

"The joint venture structure will allow the companies to offer a unified product to clients both in Europe and the Americas, providing connectivity between their respective networks with a single ticket," they said in a joint statement.

British Airways and Iberia owner IAG is paying 400 million euros ($429 million) to Spanish tourism group Globalia for the 80% of Air Europa it does not already own.

As part of its authorisation, the European Commission is likely to force the merged entity to hand over slots and routes to other airlines to guarantee competition.

IAG offered fresh concessions on June 11 in a bid to allay the Commission's worries about the impact of the deal on Spanish short and long-haul flights.

These included making available 52% of Air Europa's 2023 slots to rivals, a person familiar with the talks told Reuters.

Ryanair, Volotea, Iberojet and Binter have signed memoranda of understanding with IAG for short-haul flights and Avianca and World2Fly for long-haul. Details were not disclosed.

EU antitrust regulators are asking whether rivals proposed by IAG to take over some of Air Europa's routes are capable of operating them and competing with IAG, people familiar with the matter said last week. (Reporting by Inti Landauro and David Latona; Editing by Alexander Smith)