Wembley builder Multiplex insists there is no prospect of it going bankrupt and leaving the stadium unfinished.
The company is still confident the stadium will be ready in May
The company expects to lose £75m on the project and has been liable for daily penalty payments of £120,000 since 31 January for not completing the stadium.
But a spokesperson for the Australian firm said: "There is absolutely no possibility of Multiplex going bust.
"It is a huge company that is working on many other schemes around the world aside from Wembley."
The Football Association announced on Tuesday it was moving the 2006 Cup final to Cardiff's Millennium Stadium because of doubts over whether Wembley would be ready in time.
Chief executive Brian Barwick made the decision after Multiplex was only able to give a 70% assurance that the stadium would be finished by 13 May.
Consists of: Multiplex Property Trust and Multiplex Ltd
Interests: Construction, development, management and investment
Key developments: Dubai Marina (UAE); Stadium Australia; Wembley
Revenue (2005): A$4.2bn
Profit (2005): A$148.1m
"Nothing has changed since the end of January, when we said there was a 70% chance of the stadium being ready for the 2006 FA Cup final," the Multiplex spokesperson said.
"We were not able to increase this to 100%, so the FA decided to make alternative arrangements."
Multiplex agreed a fixed-price contract of £445m to build Wembley Stadium - with the project set to cost the FA £757m in total.
The company already expects to lose £75m on the project.
It has also faced penalty payments of £120,000 a day since 31 January for not completing the stadium.
The total penalty payments it might face are capped at £14m.
The company will announce its interim financial results to the Australian Stock Exchange on Thursday.
As well as Wembley, Multiplex is currently working on projects in High Wycombe, White City in west London, Aberdeen and the Dubai Marina Development.
The company finished the £300m Stadium Australia, the centrepiece of the Sydney Olympics, a year ahead of schedule.