Serono SA said Friday that Germany's Merck KGaA has completed its share-purchase agreement with the Bertarelli family to take control of the Swiss pharmaceutical company.

That moves Merck closer to completion of its 10.6 billion euro ($13.9 billion) takeover, which is aimed at expanding its range of drugs and share of the global biotechnology market.

Merck now holds 84 percent of the capital and 89 percent of the voting rights in Serono, the company said.

The German company bought 66 percent of Serono's capital and 76 percent of the voting rights from the family, a statement said. Merck bought the remaining shares on the market.

Subject to clearance by the Swiss Takeover Board, Merck plans on Tuesday to offer the remaining shareholders the same 1,100 Swiss francs ($896) a share it paid the Bertarelli family under an agreement announced last September, Serono said.

Last month EU regulators gave their approval to the takeover, which Merck pursued after losing a bid to acquire Schering AG.

Serono has more than 4,750 employees and had worldwide revenues of $2.6 billion in 2005.