The agency has been handed a six-figure brief around Pizza Hut UK's restaurant and delivery businesses after winning its retained consumer work earlier this year.
The move comes after the restaurant side of the business - named Dine-In and covering 330 outlets across the UK - was sold to restructuring investor Rutland Partners.
Lexis will now handle the corporate comms press office, previously looked after by Freuds, as well as handling proactive corporate work for the Dine-In and delivery side of the business. The brief, which was awarded after a deferred decision on a pitch around the work, will also cover crisis and issues management.
Rutland Partners is set to pump £20m of investment into the business, but will run the restaurants under a franchise agreement with Yum! Brands.
Linda Reddington, chief operations officer at Lexis, said: 'As part of our corporate work we plan to communicate with a wide range of stakeholders in regards to the transformation around the Dine-In side of the business, and the team that is driving this transformation.'
She added: 'We looking to support the management team in publicising the investment and maximising that news. Our messaging will focus on the fact that Pizza Hut is a modern, relevant brand in the casual dining market in the UK.'
PRWeek revealed Pizza Hut had first appointed Lexis for consumer work in March as it fought off increasing pressure from rivals such as Domino's Pizza.
In total, £60m is set to be invested in the restaurants.
Rutland Partners will operate them under a long-term franchise agreement from Yum!, which will continue to act as franchiser and receive royalties from Rutland.