Will Mould and Paul Stanway have launched XYZ after leaving Slice last year.
Included in XYZ's offer will be experiential expertise to PR agencies. Mould, who is MD of the new agency, said: 'We're looking to work with lots of different agencies, and aim to use our experience with high-level clients such as Nike.
'We feel there is a gap to be filled in the market, and our work is likely to include helping on pitches, or fulfilling agencies' events-based work.'
The pair will work with a team of three freelancers, but plan to expand during the course of the coming year.
PRWeek revealed that Mould and Stanway were leaving their respective roles as director and creative director of Slice.
Their departures came after 14 years at Slice for Mould and nine years for Stanway.
It followed the agency's merger with Mischief, after Mischief was acquired by Slice owner Engine Group in 2011. The move was seen as an attempt by the group to strengthen its consumer offering.
Mischief CEO Mitchell Kaye told PRWeek at the time of the pair's departure that it would lead to 'a new era' at the agency.