Administrators from Grant Thornton are now in charge of the Welsh based firm which is one of the sector’s biggest names and built the roof of the Aquatics Centre for the London Olympics.

They plan to keep on 80 staff to see out contracts and let 430 go imminently.

Grant Thornton senior partner Alistair Wardell said: “This is a devastating blow, not just for the Rowecord workforce which will be affected, but for the Welsh economy as a whole.

“It is also likely to have an impact on a number of other companies along the M4 corridor that up until now have been suppliers to Rowecord.

“Among our roles as administrators will be to explore which, if any, parts of the business can be salvaged and whether any jobs can be saved.

“A number of Rowecord employees will be retained in the short term post-administration to complete work in progress.”

Rowecord is currently working on major projects at the Dover Docks and the British Museum and recently built the blast furnace for Tata at Port Talbot, where it has 120 people on site providing general maintenance.

Andrew Hoppe, Rowecord Managing director, said: “It is with great regret that we have had to come to the decision to place the business in the hands of the administrators.

“Working with key business partners and the Welsh government, we have exhausted every option to sustain the business for the future.

“We will be looking to mitigate how this development may impact on the workforce.

“We are proud of all we have achieved over 40 years of trading and I’d like to take this opportunity to thank our customers, suppliers and other business partners.”

“This is a very sad day. We are a family-run company and have a hugely committed, highly capable workforce.

“Above all I would like to thank them for their fantastic part in the Rowecord story and express our deep regret for the impact this will have on them and their families.”

A Welsh Government spokesperson said: “This is very disappointing news especially for the company, its employees and their families.

“The Welsh Government has worked closely with Rowecord to support the business and offered assistance to the maximum level allowable within state aid rules.

“However, the offer was not taken up as Rowecord decided that it is in the best interests of its employees and partners to file for administration when a buyer for the business may be identified.

“In the meantime we will ensure that as much support as possible is made available to the employees including the Welsh Government ReAct programme.”