Walmart has made it official, hiring former Target media shop Haworth Marketing & Media, according to a memo from U.S. Chief Marketing Officer Tony Rogers, who said the shop's role will go "well beyond" that of a traditional media agency.

The move follows Walmart last year announcing it would part ways with Mediavest effective at the end of the current fiscal year Jan. 31. Paving the way for today's move in April, Target announced it would part ways with Haworth, owned 49% by WPP, in favor of WPP's GroupM, which set up a dedicated shop Arrow Partners for Walmart's rival.

Walmart confirmed in April it was in talks with Haworth, but has declined until today to officially acknowledge it was hiring the shop. Walmart spent nearly $2.1 billion on advertising in the U.S. in 2015, according to the Advertising Age Datacenter, including $621 million in measured media per Kantar Media.

"Haworth will play a number of roles for the Walmart U.S. marketing team, well beyond those of a traditional media agency," Mr. Rogers said in his memo. "These roles include media planning and placement, strategy for brand integrations and strategic partnerships in the marketing, media and entertainment arenas. Haworth's expertise in delivering compelling media solutions, combined with their positioning in the media and entertainment industry, will make them a tremendous resource for us."

While Publicis Groupe lost out on Walmart's U.S. media, it later picked up business last year at the expense of Interpublic's Martin Agency as Walmart consolidated much of its U.S. creative work there. And Saatchi & Saatchi veteran Andy Murray, who became chief marketing officer of Walmart's Asda in the U.K. last year, named Publicis Groupe's Saatchi and Zenith to lead creative and media duties at Asda.

Haworth has a longtime relationship with Michael Francis, the former Target chief marketing officer who worked with the agency for years there. Then Mr. Francis brought Haworth on board at Dreamworks Animation during his three-year stint as CMO there, which ended in August 2015, less than five months before he began work as a consultant with Walmart.

Haworth, which has offices in Minneapolis and Los Angeles, is "excited to start this new partnership with Walmart," said Haworth CEO Gary Tobey in a statement supplied by Walmart. "We look forward to the ways we'll tell Walmart's story to the world," he said, adding that the retail giant has "tremendous momentum."

Walmart has had 10 consecutive quarters of comp-store sales growth, including a 1.2% U.S. gain in the fiscal third quarter, even as some key competitors have struggled of late, including Target, which saw same-store sales decline 0.2% for its fiscal third quarter and flat for the first nine months of the year, and Dollar General, which saw same-store sales decline 0.1% for its most recent quarter. Even Kroger Co., whose top-line growth has been the envy of big supermarket retailers for a decade, saw same-store sales growth rise only 0.1% last quarter amid food price deflation.