Havas Advertising, Paris, is planning to significantly expand its Campus agency network through a series of global acquisitions. Expansion projects now are under way in seven markets, said Campus President Jean-Pierre Audour. The aim is for Campus, with billings of $520 million in the first half of 1999, to be present in the 12 countries or regions responsible for 85% of world ad billings. Negotiations include two agencies in the U.S., one agency in Brazil and South Korea, and two agencies in Japan, Mr. Audour said. Campus hopes to announce the Brazilian, Korean and at least one U.S. acquisition by yearend; the Japanese acquisitions should be completed by mid-2000. Campus also is prospecting for acquisitions in Hong Kong/China, the Benelux countries, Argentina, Australia and several Eastern and Central European countries, Mr. Audour said.