Tennis champion Serena Williams is set to join financial-services advisory and strategic-investing firm Consello Group with former Citigroup M&A co-chief Mark Shafir, according to people familiar with the matter.

Consello was started by Declan Kelly, who had been chief executive of advisory firm Teneo until 2021. More recently he has been aggressively building the new firm, bringing in National Football League star Tom Brady and other business heavyweights as partners.