The salaries of ground staff at German airline Lufthansa are set to increase by up to 18% after an agreement was reached in a running collective bargaining dispute. Employees will receive more pay in two stages over a period of 24 months, Lufthansa and the powerful verdi trade union said in Frankfurt on Thursday. In addition, an inflation compensation bonus of €3,000 ($3,247) and other allowances will be paid. The agreement – initially announced late Wednesday – was reached with the help of a three-day mediation led by the eastern state of Thuringia’s Premier Bodo Ramelow and the former head o…