According to an HP spokeswoman, the company is "continuing its marketing reinvention by consolidating its media and search spend with Omnicom's PHD."
"This change helps to create competitive advantage in the way we develop creative work while leveraging data and insights to improve marketing effectiveness," the spokeswoman added. "It also helps us to improve our cost structure so that we are able to continue to invest in marketing innovation."
During an interview with Ad Age last summer, HP Chief Marketing Officer Antonio Lucio said the company was dedicating about 65% of its media spending to digital in 2016, which was also the case the previous year. He added that search, mobile and social are also key focus areas.
In 2015, the company spent about $95 million on measured media in the U.S., according to Kantar Media.
Representatives from Essence, which was acquired by WPP at the end of 2015, were not immediately available for comment.
PHD, Ad Age's 2017 Media Agency of the Year, began working with HP in 2009 when Omnicom Media Group won the global traditional media planning and buying business from Publicis Groupe's ZenithOptimedia.
Between March and June of last year, PHD snagged more than $1 billion in new business, including global accounts for Volkswagen Group and Carnival Corp., Old Navy's digital work, Delta Airlines in the U.S. and MailChimp.