Procter & Gamble Co. has shifted its Tampax account to Publicis Groupe from Leo Burnett Co. sibling Publicis Worldwide, the company said.

The assignment affects the brand-agency leadership assignment, a general-contractor role overseeing other marketing-services shops for Tampax globally. It doesn't affect P&G's bigger Always brand or the related global assignments for feminine-hygiene products Whisper, Discreet and Naturella, which remain with Leo Burnett. That business is more global than Tampax, which is mostly in North American and Western Europe.

The change takes effect with the beginning of P&G's fiscal year July 1. The account had been with Leo Burnett since P&G acquired the brand in 1996. Tampax got around $44 million in U.S. measured media in 2012, per Kantar Media.

"As we refresh our strategy for continued growth for the brand, we believe the time is right for a new approach in our communications, including an agency change, and that Publicis can provide a fresh creative approach to help us with our growth plans," P&G spokeswoman Tressie Rose said in a statement.

Tampax is the No. 1 U.S. tampon brand, with a 45% share of the $1 billion market, according to Nielsen data from Deutsche Bank. But the brand lost a percentage point of share last year, continuing losses since rival Kimberly-Clark Corp. launched U by Kotex three years ago. Always has held up better than Tampax against U by Kotex.

Tampax hasn't had a TV spot on air since September, according to Ispot.tv, though much of the brand's spending is in print and digital. Much of Burnett's most recent work focused on performance comparisons vs. U by Kotex.

Starcom Mediavest Group handles media planning and buying, while Leo Burnett handles digital, MSL handles PR and Arc Worldwide handles shopper marketing. The brand-agency leadership shift doesn't immediately affect other assignments, but Ms. Rose said, "We will work that point with Publicis during our transition planning."