Wholesale and retail trade is the largest sector in the citys economy, contributing 24.0 percent of Bangkoks gross provincial product. It is followed by manufacturing (14.3%); real estate, renting and business activities (12.4%); transport and communications (11.6%); and financial intermediation (11.1%). Bangkok alone accounts for 48.4 percent of Thailands service sector, which in turn constitutes 49.0 percent of GDP. When the Bangkok Metropolitan Region is considered, manufacturing is the most significant contributor at 28.2 percent of the gross regional product, reflecting the density of industry in the Bangkoks neighbouring provinces. Automotive industry in Thailand based around Greater Bangkok is the largest production hub in Southeast Asia. Tourism is also a significant contributor to Bangkoks economy, generating ฿427.5bn ($13.38bn) in revenue in 2010.. Most of Thailand's service sector exists where?