ByJohn S. McClenahen There are times -- when a company is being sold or when it's making a public stock offering -- that knowing the worth of the firm is a strategic must. However, more than two-thirds of U.S. fast-growing companies don't know what they're worth, says PricewaterhouseCoopers (PwC). Only 29% of what the global professional services firm terms "trendsetter" companies report knowing their current valuation. And 9% expect to have a current valuation completed during the next 12 months. However, 44% of the companies PwC surveyed have no current valuation -- and have no plans to do one. Some 15% report once having a current valuation but say it is no longer current. Technology companies (27%) are slightly less likely than non-tech companies (31%) to have a current valuation, says PwC. Manufacturers and service are equally likely at 29% to have a current valuation.