You are not supposed to use corporate font in your logo since they custom designed exclusively for a particular company.
For instance, Bienvenue is a proprietary typeface for France Télécom and, though it is available for download on Rapidshare and some torrent sites, it is illegal to use the font anywhere.
Bienvenue is an exclusive corporate typeface. It was designed in 2000 by Jean François Porchez for France Télécom, the leading French telephone and internet company. The type family was developed in conjunction with Landor Associates, who redesigned the corporate identity. It is intended for use in all France Télécom communication and advertising. link.