(i) Cities provide markets and also provide services such as banking, insurance, transport, labour, consultants and financial advice, etc. to the industry.
(ii) Many industries tend to come together to make use of the advantages offered by urban centres.
(iii) In the pre-independence period, most manufacturing units were located in places suitable for overseas trade like Mumbai, Kolkata, Chennai, etc. So, these cities became pockets of industrially developed urban centres.