The three men were immediately in contact with their families. They were expected to return to Dubai on Thursday, where they work for Nokia Siemens Networks.
The three apparently strayed into waters claimed by Iran while on a fishing trip.
Iran's Ambassador to Finland, Reza Nazarahari, told YLE that the matter was resolved because relations between the two countries are excellent. He that during negotiations it quickly became clear that the businessmen had been in Iranian territorial waters by accident and stressed that the area where the incident occurred is "very sensitive".
The men were arrested near the island of Abu Musa. The question of sovereignty over the island is a long-standing matter of dispute between Iran and the United Arab Emirates. Iran took control of Abu Musa 15 years ago.