NEW YORK,(Reuters) - Standard & Poor's said Wednesday that hotel company Starwood Hotels & Resorts Worldwide would replace building materials maker Armstrong Holdings on the widely watched S&P 500 index.

The change will be effective at the close of trading on Thursday, S&P said. Armstrong is being pulled from the gauge for lack of representation. The S&P 500 is tracked by fund managers and changes to the index are often followed by heavy trading in shares of the companies affected as funds' holdings are adjusted to match the gauge.