XO Holdings gets down to the Xs and Os of business telecom services. Through its operational subsidiary XO Communications, the company provides telecommunications services to large corporations, small and midsized businesses, government agencies, and other telecom carriers via a network of about 1.6 million miles of metropolitan fiber. XO Communications offers local and long-distance voice, dedicated Internet access, private networking, data transport, and managed services such as Web hosting and bundled voice and data services. The company has customers in about 85 US markets and internationally. Billionaire financier Carl Icahn owns the company through his ACF Industries.