The opening of the multi-million-pound Swanwick centre has been delayed for nearly six years by software integration problems.
A Nats spokesman said: "There are now less than 100 days before Swanwick comes online on 27 January. "The programme is on schedule and meeting its major milestones, he added.
The launch date for Nats' new Prestwick centre suffered from the economic fallout of the 11 September attacks. The Government recently agreed to a Nats proposal to delay the start of construction work on the new Scottish air traffic control centre in Prestwick for up to two years. Officials blamed the decision on the downturn in the airline industry following the terrorist attacks in the US.
Nats officials now estimate that the new Prestwick centre will open in 2010, although they said design work and IT projects will continue in the meantime. A Nats spokesman said, "We will continue to look for an off-the-shelf software system which will perform the task of handling traffic over the Atlantic and across Scottish airspace."