Boeing Co (BA.N) and Guangzhou Aircraft Maintenance Engineering Co Ltd (GAMECO) will establish two 767 freighter-conversion lines next year, company executives said on Tuesday, citing high air cargo demand. GAMECO, a maintenance, repair and overhaul (MRO) provider part-owned by China Southern Airlines Co Ltd (600029.SS), had already been running three 737-800BCF lines converting passenger planes through earlier deals with Boeing. The 767 deal will make it Boeing"s biggest freighter conversion centre globally, GAMECO CEO Norbert Marx said on the sidelines of Airshow China, the country"s biggest air show. Airlines and leasing firms have been rushing to permanently convert older passenger jets into freighters since the start of the pandemic, betting on a boom in e-commerce as the value of used planes tumbles. read more Marx said air cargo demand was strong, in part because of to a restructuring of the global supply chain. The conversion boom is also helping aviation MRO groups offset some of the lost business from the decline in passenger flights.