Bulcke, who heads Nestle's Americas division, will take over April 10, the company said. Peter Brabeck-Letmathe, the chief executive, will remain as chairman.
Five of seven analysts surveyed by Bloomberg had expected Nestle to break a tradition of naming veterans to the top job and appoint Polman, who joined the company from Procter & Gamble in 2006. Analysts say Polman was the architect of a buyback plan that sent Nestle shares surging last month. Bulcke started working at Nestle 28 years ago.
"The fear that Polman may leave is not unrealistic," said Barbara Ambrus, an analyst at Landesbank Baden-Wurttemberg in Stuttgart, Germany. "The buyback is widely credited to Polman, as well as improved and more open reporting."
Nestle shares fell 19 Swiss francs, or 3.6%, to close at 510 francs, the steepest decline since August 10. Before the announcement, they were set to close at a record high.
A Nestle spokesman, Francois Perroud, said that Polman had "stated clearly" that he was not leaving the company,
Brabeck-Letmathe had let Polman handle conference calls on days that earnings were released, prompting speculation for more than a year that he was the likely successor at Nestle.
Bulcke began as a marketing trainee at Nestle's headquarters in 1979. He worked at Nestle divisions in Peru, Ecuador and Chile, and also headed marketing in Portugal, the Czech Republic and Germany.
The stock rose 9.5% on Aug. 15, the most in five years, as Brabeck-Letmathe announced an unexpected stock buyback of 25 billion francs and said the company no longer planned major acquisitions.
Jon Cox, an analyst at Landsbanki Kepler in London, said the buyback was probably instigated by Polman.
Brabeck-Letmathe spent more than $30 billion on acquisitions to create a company with more than twice the revenue of Kraft Foods, Nestle's main competitor. To keep meeting growth goals, his successor must add at least $4 billion in sales a year without making purchases, since Nestle now has turned away from that strategy.
Nestle said last month that its annual budget for purchases would drop to about 2 billion francs. It spent almost five times that to buy the Gerber baby food and medical nutrition units from Novartis this year.
Nestle acquired more than 60 companies under Brabeck-Letmathe, adding such products as Ralston Purina pet foods and Dreyer's ice cream.
From the September 24, 2007, Prepared Foods e-Flash