OSLO, June 28 (Reuters) - Three Norwegian labour unions have agreed to a wage deal with the owners of floating offshore oil drilling rigs, preventing the outbreak of strike action that would have disrupted exploration, the unions said late on Wednesday.

The deal between the Norwegian Shipowners' Association and the Industri Energi, Safe and DSO labour unions comprises 7,500 workers.

Unions had said that 1,644 workers on 12 rigs would go on strike initially if the talks failed, but would not disrupt the current production of oil and gas.

A strike could also have escalated within days, potentially impacting output at a later time.

Safe, Industri Energi and DSO negotiated on behalf of workers on mobile offshore units as well as platform drilling crews on permanent installations. (Reporting by Terje Solsvik, editing by Nora Buli)