China signed its biggest aircraft export agreement, in terms of both number of jets and contract value, Tuesday at the 7th China International Aviation and Aerospace Exhibition in Zhuhai city of southern Guangdong province. The Commercial Aircraft Corporation of China, Ltd. (COMAC) will sell 25 ARJ21-700 regional jets to GE Commercial Aviation Services of the United States. Vice Premier Zhang Dejiang, who announced the opening of the six-day airshow, attended the signing ceremony of the sales contract. The deal is valued at five billion yuan (733.1 million U.S. dollars).The first jet will be delivered in 2013 and then another will...