Credit Suisse Group AG is close to resolving a U.S. tax-evasion probe with an agreement that might include a penalty of more than $1 billion, after creating a separate entity last year to house the businesses involved.

The resolution of the investigation may also include a guilty plea, according to a person familiar with the talks who asked not to be identified because the matter is private. The new unit, CS International Advisors AG, was incorporated in December with a Swiss banking license. In February, Credit Suisse moved its U.S. cross-border business into the fully owned entity, according to records from the Commercial Register of the Canton of Zurich.