This paper investigates the time series of realized correlations between global industries and the world market over the 1979–2008 period. The behavior of industry correlations is characterized by long-term swings, with a period of historically low correlations in the late 1990s. The Telecommunications and the Financials industries show a positive secular trend. Global industry correlations move countercyclically. Furthermore, there is evidence that industry correlations are higher for market downside moves than for upside moves.