Bucharest's economy is centred on industry and services, with services particularly growing in importance in the last 10 years. The headquarters of 186,000 firms, including nearly all large Romanian companies, are located in Bucharest. An important source of growth since 2000 has been the city's rapidly expanding property and construction sector. Bucharest is also Romania's largest centre for information technology and communications and is home to several software companies operating offshore delivery centres. Romania's largest stock exchange, the Bucharest Stock Exchange, which was merged in December 2005 with the Bucharest-based electronic stock exchange Rasdaq, plays a major role in the city's economy. 