Around a dozen jobs have been lost after a Sunderland naval engineering firm moved its operations.
UK Docks has closed its site on Port of Sunderland’s south docks to focus attention on servicing its ship repair contracts on Teesside.
Fewer than 30 people were employed at the site, the majority of whom have moved.
The South Shields-based firm, which originally brought the mothballed and moribund Wear Dock back to life in 2002, has begun work on a £150million contract which will see Royal Navy ships regularly serviced and repaired in the region over the next decade.
The 90-metre long HMS Enterprise was the first to arrived on the Tees last month.
UK Docks' director Jonathan Wilson said: "Sadly, it’s a question of resources as much as anything else - that and the fact that the single Wear Dock is not big enough to accommodate modern vessels operating in the North Sea or any of the Ministry of Defence work we have now taken on.
"Sunderland is actually quite a difficult centre to operate because with it only having one dock, it means we had to strategically operate so that one job seamlessly follows another, whereas if you have two dry docks you can operate continually by running contracts alongside each other.”
Plans to reopen a second dock at Sunderland never reached fruition.
Jonathan added: "It’s disappointing to leave because we put so much work into reviving Wear Dock and bringing it back to life.
"At least we go in the knowledge that the dock operated for almost two decades providing employment and is in an infinitely better state than it was what when we originally took it on.
"We have also successfully managed to transfer the bulk of the small workforce at Sunderland across to Middlesbrough, so we’re pleased about that."
Family-owned UK Docks, launched by former shipyard worker Harry Wilson in South Shields in 1995, won national awards for the way it bucked the trend by re-opening dockyards that had been closed all around the country.
The company successfully re-opened docks on the Wear and Tees and also opened boat repair services on Tyneside, at Gosport and Cremyll in Cornwall and at Whitehaven in Cumbria.
Jonathan Wilson added, said: "What happens to the Wear Dock in the future is out of our hands.
"It’s hard to describe the challenge it represented for us in 2002 as we had a real task on our hands to get it up to the stage where it was operational again.
"But once we did, we were able to achieve our ambition of offering dry dock and afloat facilities in Sunderland for design, construction, repair and engineering."
Port director Matthew Hunt said: "I think it goes without saying that we never like to see people lose their jobs and we wish those affected by this all of the best in their search for new employment.
"However, whilst it’s an end of an era for UK Docks, it’s the start of a new era for the Port and the Wear Dock, which has already gained a lot of interest from both existing businesses on the site and from prospective tenants.
"The Port has grown rapidly over the past decade, evolving from what was once a traditional maritime port into a mixed-use site housing businesses from a wide range of sectors and we hope this continued growth will lead to the creation of more jobs in the future."