Sustained strong sales levels and higher capital spending by many of Iowa’s largest employers created more optimism among business leaders for the coming six months. The fourth-quarter Iowa Business Council Overall Economic Outlook Survey Index (OSI) rose to 64.7, more than three points higher than three months ago and 17 points higher than the year-ago index reading of 47.7. “This quarter’s survey results indicate that many companies are expanding their operations, possibly anticipating greater consumer purchasing activity in 2011,” said Tom Aller, president of Interstate Power & Light and 2010-11 chair of the Iowa Business Council. “We’re still cautious, however, in our employment projections.”