By Ilaria Grasso Macola Lufthansa is reportedly in talks to sell a stake in its aircraft maintenance business, Lufthansa Technik. According to Reuters sources, the airline is to offload between 20 and 30 per cent of its stake and was attracting more interest from financial investors than rival firms. The airline is also expected to commence talks with private equity backers in December, with a forecast valuation of between €6bn and €8bn (£5.2bn and £6.9bn). This means the carrier could receive a few non-binding offers by January, German business newspaper Handelsblatt first reported. Lufthansa…