Advertising agency JWT says it is closing its 118-year-old Chicago office, which at one time had 800 employees.

Citing a "difficult economic period," agency officials said Friday its work for clients Kimberly-Clark and Nestle would be carried out at its offices in New York, The Wall Street Journal reported.

Unnamed sources told the Chicago Tribune the status of JWT's biggest remaining local account, the Illinois Bureau of Tourism, is under review, and that if it is retained, a satellite office may remain open in Chicago to service it.

Responsible for such classic American advertising staples as the "Oh, I wish I was an Oscar Mayer wiener" jingle, 7-Up's "Uncola" campaign and the "There's a Ford in Your Future" campaign of the 1940s, JWT lost its key Miller Brewing account in 2003, and four years later Kraft Foods Inc. (Public, NYSE:KFT) pulled its business from JWT's Chicago office, the Tribune reported.

That proved to be a crushing blow for the Chicago office of the agency formerly known as J. Walter Thompson, the newspaper said.