Ingersoll-Rand said it decided on Ireland because it already has operations there and because of the country's membership in the European Union and its stable regulatory environment. Ireland's low corporate income tax and tax deals with the U.S. make the nation an attractive locale for companies operating in multiple countries. Quanta, based in Houston, provides services to the electric power, gas, telecommunications and cable television industries. The company's stock shot up $1.39, or nearly 6 percent, to $25.07 in after-hours trading, having closed the regular session at $23.68. Shares of companies added to the S&P 500 often rise, since many investment portfolios are linked to the index. Shares of Valmont were flat at $73.88 after-hours, while TeleTech, a call-center and customer-management services provider based in Englewood, Colo., saw shares climb 63 cents, or 5 percent, to $13.58.