Join Date: Oct 2006
Location: London, UK
Programs: BA Gold, VS Silver, SQ Silver, IHG Plat Amb, Hilton Gold, Marriott Plat, Accor Silver, Radisson Prem
Posts: 16,873
In Europe (outside of the UK), AFAIK the only airport where both BA and another oneworld lounge co-exists is at AMS (the BA Terraces and the JAL Sakura, although in different areas (BA in D and JAL in E)).
The lounge BA use in FRA is actually the JAL Sakura lounge.
CDG, for example, has the AA Admirals Club and the CX lounge, although the CX lounge closes in the early afternoon.