Oliver Wöhrl has given up as chief executive of Wöhrl, a major German department store chain owned by his family that is trying to avoid insolvency proceedings after applying for bankruptcy protection for one of its subsidiaries. The head of the supervisory board, Andreas E. Mach, is taking over his position. An attorney, Christian Gerloff, has been appointed as chief restructuring officer. Wöhrl, which is also a major retailer of sporting goods like other German department stores, will probably shrink its store network, which now counts 34 locations throughout the country. Its losses apparently increased in the year ended last July 31 on lower revenues of around €300 million