Sard Verbinnen & Co. is handling Gap's decision to spin off its fast-growing Old Navy brand, which accounts for about half of its $16.6B revenues, as a separate company.

Richard Fisher, Gap chairman, said Old Navy's business model and customers "have increasingly diverged from our specialty brands over time, and each company now requires a different strategy to thrive moving forward."

The Gap has struggled with higher prices than Old Navy, changing consumer preferences and competition from chains such as Zara and H&M.

It will be core of a yet-to-be-named $9B company with sister brands Banana Republic, Athletica, Intermix and Hill City. More than 230 Gap stores will be closed.

The split-up is expected to be complete in 2020. Both companies will maintain HQ in San Francisco.

SVB's John Christiansen, Meghan Gavigan and Devis Broda handle media for Gap's split-up strategy.