Heathrow Airport Holdings - the company formerly known as BAA - had its ownership of Stansted brought into question when the Office of Fair Trading referred the company's holding to the Competition Commission (CC).
After a long inquiry the CC ruled that BAA's airport ownership was uncompetitive.
The commission ruled in 2009 that BAA must sell Gatwick and Stansted and one of either Edinburgh or Glasgow airports. Gatwick had already been sold by the time of the ruling and since then BAA has sold Edinburgh.
More top news
Actress and campaigner tells ITV News the only way to end the trade in illegal ivory is for the West to stand up to Beijing.
Former chief inspector of South Yorkshire Police David Sumner says Liverpool supporters were not 'completely innocent'.
The Queen has come to the aid of her grandson in what has become an escalating online 'face-off' between the Prince and the First Couple.