Government-linked corporations play a substantial role in Singapore's domestic economy. As of November 2011, the top six Singapore-listed GLCs accounted for about 17 percent of total capitalization of the Singapore Exchange (SGX). These fully and partially state-owned enterprises operate on a commercial basis and are granted no competitive advantage over privately owned enterprises. State ownership is prominent in strategic sectors of the economy, including telecommunications, media, public transportation, defence, port, airport operations as well as banking, shipping, airline, infrastructure and real estate.