The airport was taken on by the Ministry of Civil Aviation in 1949, and though it was mooted for return to military use, this never happened, with it taken over by the British Airports Authority in the 1960s, with a terminal building opening in 1969 and further expansion between 1988 and 1991, and again from 2007 to 2009. In 2012 it saw more than 17 million passengers, and this year it was sold to the Manchester Airports Group after BAA was told to sell it by the Competition Commission.
For more, see http://www.stanstedairport.com/about-us/stansted-facts-and-figures/airport-history