This was addressed once before, without definitive results:

http://typophile.com/node/302

it's still a curious case, thx by the way.

I think it is a customised Novarese’s Augustea (see first answer in the older thread).
Unfortunately that design is digitally available only in an inscribed version (http://new.myfonts.com/fonts/efscangraphic/augustea-open-sb/alternate_cu...).
The one Yves points to in the other thread is a completely unrelated design, which appears to bear the same name (http://new.myfonts.com/fonts/berthold/augustea-bq/).

somewhere in digital black hole:

Augustea: Fanderia Caratteri Societa Nebiolo, Aldo Novarese/Alessandro Butti 1951 and Nova Augustea AN 1964
(eccentric tops of N and M)

Jan, are you saying there was a digital version?

Yes, OPTINovaAugustea, Castcraft Software, Inc. 1990-1991
but this is all I know about it, sorry Riccardo.

http://www.terminaldesign.com/lettering/logotypes/barneys-new-york/

Thank you Akira!
(it seems that the original logo still could have been based on Augustea)

Have you asked Barney?

"it had been auto traced from an old scan in 1993"
The story turned the clocks back to early nineties. I had been redoing some logos for clients, who had only crappy business cards...
Thanks Akira!