AMP Capital is buying on behalf of investors in its Global Infrastructure Equity strategy. : In November 2013, a consortium made up of private investment firm Ardian and Spanish airports operator Aena SME acquired the LLA concession for £394.4m (€451.3M) in equity value from TBI, a joint venture 90% owned by Abertis Infraestructuras, and 10% by Aena. AMP Capital said today it is buying Ardian’s stake in the UK’s fifth-largest airport on behalf of investors in its Global Infrastructure Equity strategy.