MILAN (Reuters) - The rationale for a merger between Italy's Saipem and Norway's Subsea 7 is to combine the fleets of the two energy services companies to service customers quicker and cut costs, the CEO of the Italian group said on Wednesday.

The two companies announced on Sunday their intention to merge to create a global leader in offshore energy services.

The combined group, which is not expected to get authorities' approvals until the second half of 2026, will have a fleet of around 60 vessels to serve the upstream oil industry and perform offshore drilling, installation, and decommissioning.

"The strategic rationale is to combine Saipem and Subsea 7's fleets... this will allow us to serve our customers more efficiently, more promptly, with shorter schedules and lower costs", Saipem Chief Executive Alessandro Puliti said at a press briefing.

He said the group's legacy projects would be either completed or almost completed when the tie-up becomes operational so are not the main driving force for the deal.

Saipem is facing hurdles to finalise an offshore wind project at Courseulles-sur-Mer in France and a contract awarded by Thai Oil for the expansion of a refinery in Thailand.

Commenting on full-year results released late on Tuesday, Saipem's top executives said the group booked provisions in the final quarter to cover risks associated with the two projects.

The Italian group now expects to complete its scope of work for the French offshore wind project next year, one year after the initial schedule.

The costs expected for the two projects are already included in the group's medium term financial estimates, Saipem Chief Financial officer Paolo Calcagnini told analysts.

(Reporting by Francesca Landini;Editing by Elaine Hardcastle)