From the press release:
"PARIS, 7 April 2010—There are now more than 16.3 million French records in WorldCat, following completion of batchloading projects from the Bibliothèque nationale de France (BnF), Système Universitaire de documentation (Sudoc) and the Bibliothèque municipale de Lyon (BM Lyon).
In 2009, the BnF and ABES, the agency that manages the Sudoc database for French universities, signed an agreement with OCLC to load their records and holdings information into WorldCat. OCLC then processed more than 8.8 million records for BnF and over 7.9 million records for ABES. The Bibliothèque municipale de Lyon, the second largest public library in France, contributed more than 1.3 million records to WorldCat.
With these projects complete, there are now more than 16.3 million French-language records in WorldCat. Just as the total number of WorldCat records has grown substantially in recent years to 175 million, the percentage of French-language records has also increased from 6.2 percent in 2007 to 9.6 percent in 2010."
Here's the full press release.