Passenger flights may resume shortly
The British and French aviation authorities have agreed to return the airworthiness certificates for planes which have met agreed modifications.
BA told BBC News Online that it hoped to resume passenger flights from London to New York in October though there was no firm date yet.
And Air France said it plans to resume commercial Concorde services from November.
BA and Air France each have one plane that meets these requirements, while work is nearing completion on others.
The Concorde fleets belonging to British Airways and Air France have been grounded since one crashed near Paris in July 2000, killing 113 people.
The air worthiness certificates were withdrawn following the accident.
British Airways confirmed that the Civil Aviation Authority and its French equivalent, the DGAC, agreed to return the certificate to the first of its Concordes to be completely modified on Wednesday afternoon - paving the way for passenger flights to be resumed shortly.
British Airways needs three Concordes back in service before passenger flights can be resumed.
BA said on Wednesday that two others of its aircrafts were in the process of being modified.
Mike Street, BA's director of customer service and operations, said: "British Airways has always said that we would only resume Concorde services once we were convinced we could do so safely.
"The package of safety measures developed by the manufacturers and agreed today by the regulators enables us to achieve this".
Safety improvements
The CAA's head of design and production standards said: "As an independent specialist regulator, the CAA has monitored all the work and the modifications very closely and is now satisfied that the changes will prevent any future catastrophic accident such as occurred at Paris. "
This could allow passenger services on the supersonic jet to resume within weeks.
Mike Bannister, BA's chief Concorde pilot, said: "After months of hard work by the manufacturers and our engineering teams, it is exciting to be one step closer to getting Concorde back into the air."
Air France told BBC News Online: "Air France will continue to train crews in order to resume commercial service between Paris and New York as from November."
Both airlines have made extensive modifications to their fleets to prevent a repeat of last year's crash, caused when debris from a burst tyre pierced a fuel tank, resulting in a fatal fire.
Tougher tyres have been introduced, fuel tanks have been fitted with a bullet-proof lining, and other procedural changes have been made.
The modifications performed well in successful test flights conducted by BA.