The deal, which is subject to regulatory approval, will enable to extend its reach into India's direct marketing and customer relationship management industry.
Chateaux Hospitality, which operates in India under the name Rams, is headquartered in Gurgoan and has offices in Mumbai and Bangalore.
The agency's clients include American Express, GE, GlaxoSmithKline, Nestle and Eli Lilly.
Its unaudited revenues for the year ending March 31 2007 were INR123.3m (£1.56m) and its gross assets were valued at INR211.2m (£2.67m). It was founded in 1998 and employs 148 people.
G2 Worldwide is a global marketing network that specialises in digital, direct and in-store marketing and design. It is part of WPP's Grey Group.