UK-based Craig Group has sold its search and rescue arm, North Star Shipping, to Basalt Infrastructure Partners.
North Star provides emergency response and rescue services to the offshore industry in the North Sea.
It owns and manages 31 vessels and is supported by a fleet of 50 fast rescue craft and 35 daughter craft.
North Star managing director Callum Bruce said the senior management team, staff and crew would remain.
Basalt is an infrastructure equity investment fund focusing on investments in utilities, energy and transport infrastructure in Europe and North America.