STOCKHOLM (Reuters) – Troubled airline SAS is cancelling 4,000 flights this summer due to a lack of staff and delayed aircraft deliveries, Swedish financial daily Dagens Industri reported on Tuesday. The group, which is struggling with weak demand and tough competition, launched a cost savings plan in February and plans to raise new capital, but progress has so far been limited. SAS had previously planned for 75,000 flights in the May-August period, but around 4,000 of those would now be cancelled, a spokesperson told Dagens Industri. SAS, in which Sweden and Denmark each hold a stake of aroun…