Like Agency Assessments, Pocock's yet-to-be-named company will only charge marketers for its services.
Pocock is positioning his business to handle pitches across a range of disciplines including PR, digital and direct marketing, as well as advertising.
Also, while Pocock will offer consultancy services, it is unlikely to be on a retained basis, as Agency Assessments' model is. Instead, Pocock will offer guidance for clients that are seeking advice on their agency relationships.
Pocock and Wethey's working relationship, which dates back 25 years, will continue on an informal basis, enabling the two companies to help each other out on client conflict.
Pocock has worked at Agency Assessments for six years, most recently on the £80 million global Sony Ericsson pitch, which was won by Saatchi & Saatchi.
He first worked with Wethey 25 years ago, when they set up the creative agency Wethey Scott Pocock.
The two parted company in 1988 when they sold the agency to set up their respective companies, Agency Assessments and the creative hotshop Pocock & Co.
Wethey said: "Stuart is a long-term friend and colleague and he goes off with my blessing."
He wants to run his own business again and there's been so much pitch activity recently we hadn't been able to take it all on.
Agency Assessments is currently conducting the £15 million Thomson Holidays pitch, which was called last month.