By Stine Jacobsen and Louise Rasmussen COPENHAGEN (Reuters) -Denmark's Orsted and Vestas, two of the world's top offshore wind power groups, urged European nations on Wednesday to speed up permitting, improve auction terms and invest in power grids to deliver their potential for strong growth in the sector. The offshore wind industry, facing a near-frozen U.S. market amid President Donald Trump's opposition to renewables, is increasingly looking to Europe for opportunities. Vestas, the largest wind turb ...