Chennai’s economy is based on the automobile sector, software services, hardware manufacturing, healthcare and financial services. 1991 Census charted the bifurcation as the city’s workforce was mainly engaged in trade- 25.65%, manufacturing- 23.52%, construction- 6.3%, transportation- 10.72% whereas other services constituted- 31.8%.
Companies like Infosys, TCS, Wipro, Satyam, HCL, EDS, Accenture, Sun Microsystems and HP are based in the city’s software and biotech parks. Software exports of Rs.1,442,140million during 2006–07, earned a name for Chennai as a second-largest exporter of software in the country, behind Bangalore.
The Industrial hub of South India, Chennai, has about 45% of India's auto components and 27% of the vehicle industry. Chennai houses various manufacturing units of various automobile giants across the globe like Mitsubishi, Ford, Hyundai, Ashok Leyland, Royal Enfield, TAFE, MRF, Dunlop as well as TI Cycles to name a few. The Integral Coach Factory manufactures railway coaches and other rolling stock for Indian Railways. Chennai has acquired the name as being the Detroit of Southern Asia. This was possible because of such an industrial expanse.
India's leather exports constitute a share of more than 50% that comes from Chennai. An SEZ (Special Economy Zone) has been set up which manufactures apparels and footwear. The said SEZ is located in the southern suburbs of the city. Chennai has an electronics manufacturing hub. This is a place where many MNC’s have set up electronics and hardware manufacturing plants. Nokia, Motorola, Samsung, Dell, Flextronics and Foxconn are major examples in that case. Research and Development facilities have also been set up in Chennai. Various chemicals giant Dow Chemicals, pharmaceuticals giants like Pfizer along with the telecom giants like Ericsson and Alcatel-Lucent would be to name a few.
Chennai is the seat of prominent financial institutions, including the World Bank, HSBC, Citi Bank. Chennai holds three large national level commercial banks and many state-level co-operative banks, finance and insurance companies.