New Delhi, Nov. 27 -- Two of the advertising world's Big Four holding companies- Interpublic Group and Omnicom-officially merged this week. The combined entity, formed almost a year after the Omnicom Group announced it would acquire IPG, is now the world's largest media and ad agency network, with global revenue of over $25 billion.

Why is this deal important and what will it change for India's advertising industry? Mint explains.

Omnicom Group acquired IPG in a $13.5 billion deal this week. Both companies are listed on the New York Stock Exchange. Omnicom shareholders will own a little over 60% of the combined entity that will trade on the NYSE.

Together, this is now the world's largest advertising agency business, with annual global ...