A spokesman for Houlder Engineering said it had asked for prices from yards around the world, including Britain, and the best value offer came from Flensburg in Germany.
Andrew Weir Shipping Ltd is a shipping services company in a consortium that is using a German shipyard to undercut the BAe Systems yard on the Clyde.
The company, along with Liverpool-based James Fraser and Son and Houlder Offshore Engineering, has formed a consortium which looks set to win the contract to build six new ferries for the Ministry of Defence.
A spokesman for Houlder Engineering said it had asked for prices from yards around the world, including Britain, and the best value offer came from Flensburg in Germany.
The Flensburg yard is currently building similar roll-on roll-off ferries for a Turkish customer.
Ministers have confirmed that the price from the German yard is unbeatable but efforts to win some of the work for the Clyde yard are continuing.
Trade union officials emerged from a meeting with the Trade and Industry Secretary Stephen Byers saying they had been reassured everything possible was being done.
Thousands of Scottish shipyard jobs are at risk if the former Kvaerner yard in Govan fails to secure at least part of the contract.
Unfair competition
After the 90-minute meeting with Mr Byers, Danny Carrigan, Scottish secretary of the AEEU, said he was impressed with the way the minister listened to their arguments.
He was satisfied that ministers were fighting for British shipworkers and to ensure a level playing field for the MoD's orders.
Mr Byers also said officials were investigating allegations of unfair competition from Germany.
Scottish Labour MPs met Defence Secretary Geoff Hoon on Thursday afternoon to press for at least part of the order for roll-on roll-off ferries to go to Govan.
In a separate move, the unions have also invited Defence Procurement Minister, Baroness Symons, to visit the Govan yard.
A possible compromise would be to split the work between Govan, which employs 3,000 people, and other yards.
The contract for six ferries is worth £200m, but could create £1bn in spin-offs and refits.
BAE Systems Govan is the chosen builder for the Sealion consortium bid, with its Scotstoun sister yard as outfitter.
Tony Blair has dismissed as "absolute nonsense" the reported view of Defence Secretary, Geoff Hoon, that shipbuilding was a "metal-bashing" industry that no longer represented a national asset.