Todd Pendleton, the former CMO of Samsung Telecommunications America and newly appointed chief creative officer of the company's consolidated U.S. business is leaving the company, Ad Age has learned.

Mr. Pendleton joined Samsung in 2011 and launched the "Next Big Thing" campaign. The brash challenge to Apple quickly elevated Samsung's profile in the smartphone market. He announced his departure to Samsung staff, saying he plans to leave in early April.

CNET first reported the news. Representatives from Samsung did not return requests for comment.

Last year, Samsung radically restructured its U.S. marketing team amid a swift downfall in mobile sales worldwide. The Korean manufacturer has been losing market share to Apple and upstart Asian competitors. Samsung's three U.S. business units were consolidated under a new division, called One Samsung. The consolidation meant the marketing division from the mobile unit would move from Dallas, where Mr. Pendleton is based, to New York City where it would combine with the home appliances and consumer electronics units. Samsung said the move would happen early in 2015.

Peggy Ang, who led U.S. marketing for Samsung's home appliances and consumer electronics, departed the company in January.

Gregory Lee, a former CPG marketer, leads One Samsung. The manufacturer also brought in two top-level executives from CPG marketers: Vince Hudson, in March, to lead brand strategy; and Jay Altschuler, in January, to lead U.S. media operations.

Samsung never clarified Mr. Pendleton's exact responsibilities under the new structure. At some point in 2014, he began to oversee creative campaigns for Samsung's HD TVs, as well as its smartphones and tablets. A Samsung executive characterized his role as "a horizontal expansion, not a vertical one."

Mr. Pendleton, who spent 15 years at Nike before joining Samsung, is widely respected in the advertising industry. Early in his tenure, Korean executives considered replacing him but opted to keep him on given the rapid sales increases in the U.S., according to multiple executives. As CMO, he worked closely with RGA, SMG and 72andSunny, which created the humorous Galaxy spots that would become the brand's trademark in the U.S. Representatives from the agencies could not be reached for comment.

Mr. Pendleton has not decided his next move, according to one executive close to him. Multiple executives noted that several firms have expressed interest, including Sprint, which has yet to announce its incoming CMO. A new CMO is expected at Sprint by April.

Samsung's mobile division is under considerable strain, with profits falling for five straight quarters. The division shuffled through two top marketers at its Korean headquarters in the months leading up to its colossal flagship device launch in Barcelona this week. The conglomerate is one of the largest mass media spenders worldwide. In the U.S., Samsung spent $1.7 billion in advertising in 2013, according to the Ad Age DataCenter.