The publicly quoted company has agreed to buy 75% of the share capital in Indica Research, an independent research company based in Mumbai, with the option to up its stake in the future.
Indica, which has 150 staff, is a 13-year-old business turning over approximately £2m a year, ranking it among the top five research companies in India.
Ipsos has also bought Norwegian market research company, ResearchPartner, outright.
The firm was established in Oslo in 2003 and specialises in advertising, marketing and customer relationship management. Last year, it posted an £850m turnover.
Richard Mecchi, the Ipsos Asia-Pacific chief executive, said: "It was important to reinforce our presence in India, where the market research market grew 17% in 2006."
Lena Gilchrist, head of Ipsos Scandinavian, said: "The Ipsos presence in the Norwegian market will allow us to better serve our Scandinavian clients, as well as the major international firms which need an in-depth knowledge of business market in the Nordic countries."