A logo that JWT is using to celebrate its 150th anniversary features the classic "J. Walter Thompson" name along with the agency's heritage symbols of an owl and a lamp. A funny thing happened on Monday morning to carefully laid plans by the giant JWT advertising agency to announce later in the year that it would bring back its longtime name, the J. Walter Thompson Company: The chief executive of the JWT parent, Martin Sorrell of WPP, let the cat out of the bag. Mr. Sorrell made the disclosure at a breakfast at the Pierre Hotel, one in a series of executive breakfasts hosted by The Wall Street Journal. During the question-and-answer portion of the event, Mr. Sorrell was replying to a query about WPP’s “legacy creative” agencies, among them JWT, Grey and Ogilvy & Mather. After noting that JWT is celebrating its 150th anniversary this year, Mr. Sorrell told the audience that the agency has been “talking about rebranding,” and praised “the J. Walter Thompson Company brand” as “immensely powerful.” Going back to the J. Walter Thompson name would be “a slick and a good move,” Mr. Sorrell said. J. Walter Thompson adopted the JWT name in 2005, 18 years after it was acquired by WPP, currently the world’s largest agency holding group. That the agency’s senior managers are interested in reclaiming the name is not entirely surprising — a logo being used to celebrate the 150th anniversary features the J. Walter Thompson Company name along with other agency legacies like images of an owl and a lamp. Bob Jeffrey, worldwide chief executive of JWT, confirmed the name-change plans in a phone interview on Monday with a reporter who had attended the breakfast. “Gustavo and I had a lengthy presentation to the WPP board of directors last Tuesday in London,” Mr. Jeffrey said, referring to Gustavo Martinez, global president of JWT, “and we said confidentially that we didn’t plan to announce” the readoption of the J. Walter Thompson name “until the end of the year.” The timing would coincide with the exact anniversary of JWT’s opening; the agency traces its roots to a newspaper space brokerage that began operation on Dec. 5, 1864. “We felt it would be a perfect time to return to the J. Walter Thompson name,” Mr. Jeffrey said. The genesis of the decision to revive the J. Walter Thompson name is that “this is a year of reigniting the values and soul” of the agency, he added. Asked about his boss’s remarks upending the agency’s planning, Mr. Jeffrey said, “Maybe he just couldn’t help himself” because he believes the name change is such a good idea. In changing its name to JWT, J. Walter Thompson joined a lengthy list of blue-chip agencies that adopted initials in place of founder names; others include BBDO, DDB and Y&R. However, people in the advertising industry will often call JWT “Thompson,” and the agency’s legacy name has been featured from time to time on “Mad Men,” most recently during Sunday night’s episode in a reference to two accounts that Thompson handled in 1969, 7Up and Oscar Mayer.