BERLIN—A group representing Germany’s machinery industry said Tuesday it expects a weaker rebound in production this year than previously forecast because of persistent supply chain bottlenecks. The VDMA group said it now expects production to grow by 7 percent this year to a value of about 219 billion euros ($247 billion), down from the 10 percent it predicted in September. Last year, production of machinery—a major German export—dropped by nearly 12 percent. VDMA said that new orders significantly outpaced increases in production in the year’s first 10 months. “We could have produced more had the various delivery bottlenecks not been so persistent,” said the group’s chairman, Karl Haeusgen. However, companies expect to be able to work through their order backlog next year, so VDMA increased its forecast for 2022 from a 5 percent increase in production to 7 percent. A survey of 521 member companies at the beginning of December …