Buyout group Carlyle has agreed to buy airfield lighting group ADB Safegate at a valuation of about 900 million euros ($1 billion) including debt, sources familiar with the matter said. Belgium-based ADB Safegate supplies visual guidance solutions from landing to parking for airplanes, including lighting systems for airport runways as well as docking and tower systems. Private equity group PAI Partners bought ADB from peer investor Montagu in 2013 for 208 million euros.