TBI, the UK-based regional airports operator, has put three airports and an airline services company up for sale as part of a restructuring ahead of what it sees as early signs of a turnaround for the aviation industry. The company said it expected to sell its three airports in Bolivia in the current financial year as well as its Airport Services division in the United States. TBI told investors to expect a series of divestments of non-core activities over the next 18 months as the group reported near flat annual earnings growth.