Yahoo! said that Vidal had made a "personal decision to pursue a new opportunity outside the company" and that Coppel would take over as of June 1.
Terry Semel, chairman and CEO of Yahoo!, said: "Toby’s strategic vision and leadership skills make him the ideal person to lead the Yahoo! Europe business to the next important stage of its development. We’d like to thank Dom for his contributions to the company and wish him all the best in his new endeavour."
Since joining Yahoo! in 2001, Coppel has been responsible for the development of Yahoo!'s strategy and for looking at new opportunities globally, including mergers, acquisitions, investments, strategic partnerships and joint ventures.
Prior to joining Yahoo!, Coppel was managing director of Windsor Digital, an investment company founded by Semel. Before joining Windsor, Coppel was vice president at investment bank Allen & Company, and prior to that worked at Goldman Sachs International.
"The European market continues to offer huge potential for our company to provide value to consumers, advertisers and publishers. We have a strong team in place to continue to evolve our vision for the business and explore new avenues of growth through addressing the changing needs of our customers," Coppel said.
His appointment follows disappointing first-quarter results from Yahoo! yesterday, with profits down by 11% to $142m (£71m), as its new Panama advertising platform, which is designed to take on Google, has yet to kick in, pushing its shares down by more than 8% before recovering.