Aberdeenshire-based Proserv has bought KRG, a provider of precision engineering services to the oil and gas, aerospace and defence industries for the last 35 years, from majority shareholder Torishima of Japan.
The acquired firm's 170 staff in Coatbridge and Stockton-on-Tees will not be relocated and will continue to run the business as it is integrated into the Proserv group.
Proserv did not disclose the value of the deal, though it is believed to be come into the "multi-million pound" bracket.
KRG provides machining, welding, inspection and testing services, with clients including "blue chip" oil and gas equipment manufacturers, oilfield services companies and defence contractors.
Proserv said the deal reinforces its position in engineering, manufacturing, testing and after-market servicing for specialist and highly-critical subsea equipment.
Chief executive David Lamont said: "Our plan for growth is to invest in complementary world-class technologies and build on our existing range of value-added products and services.
"The acquisition of KRG is a perfect strategic fit for Proserv. They bring a broad range of technical skills and experience but, most importantly, they share our core values and ambition to be the provider of choice to our customers.
"It will be an exciting new partnership that enhances our integrated capabilities and creates significantly more capacity to develop our international business.
"It will also bring further positive benefits for employees and give them the opportunity to become involved in a broader, more diverse range of projects as well as considerable benefits to our fast-growing portfolio of clients through the delivery of an enhances service capability."
The acquisition comes eight months after Proserv acquired Velocious, an Australian-based subsea intervention and tooling company, with that deal following Proserv's buyout of US Company Total Instrumentation & Controls (TIC) at the end of 2012.
Those transactions added 20 and 300 staff to the Proserv ranks respectively.
A spokeswoman said the company remains on the look-out for further acquisitions.
By the time the KRG staff are integrated, staff numbers at Proserv will have risen to more than 2200 at 30 bases in 11 countries.
Proserv is currently on a recruitment to drive to add 75 staff to its various sites in Aberdeenshire, announced when it moved into new headquarters in Westhill's Arnhall Business Park in December.
The drive is part of plans to draft in a total of 150 staff across its operations over the next six months, continuing a recruitment drive which saw the company up its headcount by 25% between 2012 and 2013.