NOVATO -- BioMarin Pharmaceutical Inc. will allow its marketing partnership for the drug Aldurazyme to remain in place with Sanofi-Aventis following the French drug maker's  $20 billion acquisition of Genzyme Corp.

BioMarin explored exercising a change-0f-control provision in its agreement with Genzyme, the Novato company said in a filing with regulators. Under that provision BioMarin could have set its own price for full rights to Aldurazyme, which brings revenues of about $250,000 a year.

But Sanofi-Aventis responded to queries by saying " that it and Genenzyme will continue to exist after the transaction as a wholly-owned subsidiary of Sanofi, the transaction does not give rise to a right of BioMarin to terminate the Manufacturing, Marketing and Sales Agreement and initiate the buyout process contemplated by the Agreement."

According to BioMarin spokesman Bob Purcell, the company decided not to pursue the matter.

"After careful consideration of our options and in-depth discussions with Sanofi-Aventis, who reaffirmed their commitment to growing Aldurazyme, we have determined that the best course of action for BioMarin was to not exercise our change of control rights," said Mr. Purcell.

Aldurazyme, the first enzyme therapy brought to market by BioMarin, treats a rare metabolic disease.