Under the deal, a new firm, Ledwood Mechanical Engineering, takes on Ledwood's contracts and 100 of its 136 staff. The move comes a month after Ledwood slipped into administrative receivership with debts in excess of £9m.
The rescue team, which is headed by Ledwood managing director Willie McLean, is backed by the Milford Docks Company, a subsidiary of Milford Haven Port Authority.
The new firm also includes Ledwood finance director Leighton Jenkins and engineering director Alan Davies.
Davies, who with McLean and Jenkins owns a majority shareholding in the firm, said: "It's been a very difficult time. The last month has very much been a new experience for us. Ledwood Construction was a profitable, respected company with a lot of experience. It was a great shame it went."
The decision to call in the receiver sparked calls from the local MP, Nick Angier, for a Department of Trade and Industry investigation into the behaviour of a US firm, Raytheon Engineers.
Davies said they would now be more selective about clients. He said: "Some of our previous clients have been very supportive. We have already had a lot of assurances from clients."
All the employees have been magnificent and the support from clients crucial
Ledwood MD William Mclean
He emphasised that the firm was determined not to overreach and would work only on projects that would not stretch its resources and capabilities.
McLean said the deal had been a team effort. He said: "All the employees have been magnificent and the support from clients has been crucial."
Davies confirmed that the firm would no longer work on the £480m Damhead Creek gas power station in Kent, the job in which Ledwood's dispute with Raytheon arose.
Legal action is understood to be continuing between Ledwood's receivers, Ernst & Young, and Raytheon's owners, the Washington Group.
Milford Docks Company said the new firm represented a good investment. Chairman Bob Clarke said: "This has the benefit of supporting a new company which will make significant use of the port and will be an integral part of the support service to the oil industry in the haven."