Shares in Boeing fall in premarket trading in the U.S. after the company’s largest union went on strike. Its stock is down nearly 4% at $156.55 after workers rejected a contract offer that would have raised pay by 25% over four years. In 2008, a 57 day strike over pay negotiations cost Boeing an estimated $100 million a day. The strike comes at a time when the indebted plane manufacturer may require an enormous equity raise to fix its balance sheet, Robert Stallard, equity analyst at Vertical Research Partners, wrote ahead of the vote to strike. In some delivery lines, Boeing has an excess inventory of material and therefore the strike may be a good opportunity to reset supplier deliveries, he adds. Boeing’s Frankfurt listed shares trade down 4% at 141.68 euros.