The agency is the incumbent on the Heinz business in the UK and some other European markets and its decision means it will lose an account it has held for five years, leaving networks including Mediaedge:cia and OMD Europe to fight for the business.
Earlier this week, Starcom Motive defeated MindShare in a head-to-head pitch to capture the Pizza Hut account.
The account came up for pitch at the end of April when PHD decided to resign it following the fast-food giant's decision to invite Billetts to conduct its second review in as many years.
This process was instigated by Simon Wallis, Pizza Hut's retail marketing director and a former marketing manager at Pizza Hut's sister company KFC. PHD was unhappy that Wallis had asked the agency to defend the business so soon after the last review. In 2002, it successfully fought off an attempt by Zenith Media to wrest the business away.
Wallis said: "We were impressed with the proposals from Starcom Motive and MindShare and it was tough to choose between the two."
Starcom Motive will take over the account at the end of September.