The Red Consultancy, Cohn & Wolfe, 3 Monkeys and three-year incumbent Lexis will all pitch for the business with a decision expected to be made by early August.
3 will continue to work with Slice and Frank on projects, Parys Communications for its B2B work and Brunswick for its corporate PR.
Lexis has worked with the company for the last three years. Meanwhile, Cohn & Wolfe has just stopped working with O2, after a four-year relationship.
3 has over four million customers in the UK but is determined to grab a bigger share of the market.