UK regional Eastern Airways will enter the busy London City (LCY) to Amsterdam route early next year.
The move has been sanctioned by the OFT (Office of Fair Trading). It is part of a deal which will allow the Air France-KLM airline grouping to take control of Belgian airline VLM.
VLM, the biggest user of LCY, will have to surrender some peak hour LCY slots to the newcomer.
"This will ensure that passengers are not harmed by a substantial lessening of competition on a route worth over £50 million a year," an OFT spokesman said.
Eastern Airways has permission to fly up to eight times a day on weekdays starting from next January. Four of these services will operate at peak times.
But the Humberside-based airline isn't in a position to divulge any further information at this stage.
The spokesman added: "We've only just received this route approval from the OFT so we're only at the start of the planning process. I am unable to confirm a starting date, the aircraft type or the tariffs. But all will become clear soon."
Eastern Airways currently operates mainly on UK domestic routes using a 29-strong fleet of 29-seater Jetstream 41 and 50-seat Saab 2000 turbo-props. Its network was traditionally geared to serving the oil and gas industries and as a result it operates on niche routes and especially those underserved by road or rail.
It is no stranger to LCY having operated a service to Newcastle some years ago. But that route lasted only 12 months before being withdrawn.
Eastern will face a tough challenge with LCY-Amsterdam. It will be competing against VLM and KLM's turbo-prop aircraft, and BA's jets. All these carriers offer convenient schedules.
It is not a budget carrier so it will not be undercutting its rivals on price. And Eastern has no market identity in London and the Southeast. It also lacks a powerful frequent flyer programme.
But Eastern is known for offering old-fashioned standards of in-flight service. So the question is...will this be enough ?