GIP owned EDI and LGW have both left NATS and given ATC out to third parties recently. Same owner as LCY.
Actually, GIP sold the airport last year
From wikipedia:
Later in 2015, Global Infrastructure Partners which owned 75% of the facility, put it up for sale, with the agreement of Oaktree Capital Management which holds the remaining 25%.[25] A sale to a consortium comprising Alberta Investment Management Corporation, the Ontario Teachers' Pension Plan and Wren House for £2 billion was confirmed in February 2016.[3] The sale was completed on 10 March 2016.[26]