UPDATE 1-Frere's GBL ups Lafarge stake

(Adds GBL comment)

PARIS, March 5 (Reuters) - The holding company of Belgian billionaire Albert Frere and Paul Desmarais has raised its stake in French cement maker Lafarge (LAFP.PA) to just over 20 percent, France's AMF stock market regulator said on Wednesday.

The AMF said in a regulatory filing the Groupe Bruxelles Lambert (GBLB.BR) holding company now had 20.04 percent of Lafarge's share capital, up from a previous stake of just over 18 percent.

GBL said the regulator's statement dated from the situation on Feb. 29, while its own 2007 results release on Tuesday showed that its holding was 20.1 percent on March 3.

However, it also said its current holding would amount to 17.8 percent after Lafarge's purchase of Egypt's Orascom Cement, which is partly to be financed by the issue of new shares.

Lafarge shares were up 2 percent at 113.34 euros in late afternoon trade. (Reporting by Sudip Kar-Gupta in Paris and Philip Blenkinsop in Brussels; Editing by David Holmes)