The report said Publicis' bid comes after a failed merger attempt in May with Omnicom Group. Publicis, the world's third-largest ad company, has blamed its recent slowdown in growth in part on the distraction caused by the merger, which was aborted amid internal power struggles.

The new deal could be announced as soon as Monday, the Journal said, though it added that the talks could fall apart at the last minute. Publicis is scheduled on Friday to present investors with a plan for increasing digital advertising.

Sapient and Publicis were not immediately available for comment.

The news of the deal to acquire Sapient, one of the last big independent digital agencies, comes at a time when Publicis is struggling to boost growth from new forms of advertising increasingly dominated by data and technology. Publicis is also under pressure to find a way to better negotiate with Web behemoths such as Facebook Inc. and Google.

(Reporting By Michelle Conlin; Editing by Cynthia Osterman)