Plant Integrity Management has been engaged to manage an inspection and repair programme covering some of the equipment used on the Triton vessel 120 miles east of Aberdeen.
Dana's engineering and maintenance manager Derek Thomson said: "We recognise the importance of this strategic partnership and its success will ensure we continue to deliver safe and reliable operations for Triton, and potentially further UK assets as and when they come into production."
The Triton FPSO produces oil and gas from the Bittern, Clapham, Pict, Saxon, Guillemot West and North West fields.
Korean-owned Dana Petroleum took over the operatorship of the vessel from Hess in 2012, when it acquired the US firm's 28.28% stake in Bittern.
Privately-owned Plant Integrity Management has achieved rapid growth amid strong activity levels in areas like the North Sea. Formed in 2011, the company had £1.7m turnover in 2012.