European shares finished the week at a 12-year low after a day of wild swings.London was the only major market that did not end up in the red. Investors were spooked by last month’s unemployment rate in the US hitting its highest level in more than a quarter century, showing the continued weakness of the world’s largest economy. Financial stocks – banks and insurers – were the biggest decliners. Natural resources companies benefited from a rise in commodity prices. Among the standout losers was heavily indebted British company Wolseley, the world’s biggest building supplies firm. It shed 15 percent as it had to sell nearly 1.2 billion euros of new shares.