M2M was the incumbent on Estee Lauder's UK media account, while the Asian business was previously split between local agencies.
Omnicom and WPP saw off competition from Havas subsidiary Media Planning Group, a non-roster agency that also pitched for the account.
Estee Lauder, which owns the Clinique, Aveda and Aramis brands, called the review eight months ago in order to consolidate the business into one agency.
It initially kicked off the pitch, which encompasses its entire cosmetics range, in April last year, but decided to put it on hold two months later. The review was led by Estee Lauder's head office in New York.
This is the second major global win for Omnicom in a week, following Intel's decision to award OMD its $300 million global media account.
OMD beat incumbent, Interpublic's Universal McCann and Groupe's Starcom in a three-way shoot out for Intel's global account earlier this week.