Chennai, formerly known as Madras, is the capital of the state of Tamil Nadu and is India's fourth largest metropolitan city. It is located on the Coromandel Coast of the Bay of Bengal. With an estimated population of 7.06 million (2007), the 368-year-old city is the 34th largest metropolitan area in the world.

Economy
Chennai has a diversified economic base anchored by the automobile, software services, hardware manufacturing and financial services. Other important industries include petrochemicals, textiles and apparels. The Chennai Port and Ennore Port contribute greatly to its importance. The city has a fully computerised stock exchange called the Madras Stock Exchange. Chennai has the fourth largest Gross Metropolitan Product in India.

Since the late 1990s, software development and business process outsourcing and more recently electronics manufacturing have emerged as major drivers of the city's economic growth. Chennai has been rated as the most attractive Indian city for offshoring services according to A T Kearney's Indian City Services Attractiveness Index 2005.[20] Major software and software services companies like Accenture, Cognizant Technology Solutions, CSC, EDS, HCL, HP, IBM, Infosys, Satyam, Sun Microsystems, Symantec, TCS, Verizon, Wipro,Hewitt Associates, Hexaware and US Technology Resources have development centres in the city. The city is now the second largest exporter of IT and IT enabled Services in the country behind Bangalore. The IT Corridor, on Old Mahabalipuram Road in the southeast of the city houses several technology parks, is currently under construction in the outskirts of Chennai. The Mahindra World City, a Special Economic Zone (SEZ) with one of the world's largest information technology parks, is currently under construction in the outskirts of Chennai.

Chennai is the base for around 49% of India's auto components industry and 34% of the vehicle industry. A large number of the automotive companies including several global automotive companies such as Hyundai, Ford, BMW, Mitsubishi, TVS, Ashok Leyland, Caterpillar, Royal Enfield, TI Cycles, TAFE, Dunlop, MRF have manufacturing plants in and around Chennai. Nissan-Renault and Mahindra & Mahindra joint venture, Naza Automobiles and Apollo Tyres have plants under construction. The city is a major centre for the auto ancillary industry. Hyundai is in the process of setting up engine plant in the city. Several Petrochemical companies like Chennai Petro Chemicals Limited (CPCL), Manali Petro Chemicals Limited, Madras Refineries Limited (MRL), Petro Araldite and Orchid Pharmaceuticals are situated in the outskirts of Chennai.

The Heavy Vehicles Factory, Avadi produces military vehicles, including India's main battle tank: Arjun MBT. The Railway Coach building factory of the Indian Railways, the Integral Coach Factory manufactures railway coaches and other rolling stock.