Tug boat engineers at Port Hedland, Australia’s biggest iron ore port, plan to hold a four-hour work stoppage on Nov. 22, tug operator Teekay Shipping said, threatening exports from BHP Billiton and Fortescue Metals Group. The Australian Institute of Marine & Power Engineers (AIMPE) has given notice of the stoppage after rejecting an enterprise agreement which offers an additional 28 days annual leave and three annual 2 percent wage hikes. “Teekay very much regrets that the industrial action will take place, and the impact it will have not just on Teekay and its customers, but also on the Australian economy, the company said in a statement. AIMPE had canceled a scheduled work stoppage on Nov. 12 after being served an interim order to stop the action pending a vote on the enterprise agreement this week. Tug boat captains, engineers and deck hands have been demanding higher pay and more leave from Teekay following a one-third increase in iron ore shipments through Port Hedland over the past year that has stretched their work hours. Australian shipments of iron ore to China from Port Hedland, rose 6.5 percent to a near-record in October, port data released Nov. 4 showed.