The labels fear a possible influx of illegal cheap imports as copyright is lifted in Europe on 1950s recordings by stars like Maria Callas, Elvis Presley and Ella Fitzgerald.
Copyright on music ends after 50 years in Europe, but in the US copyright does not expire for 95 years.
"
I think it's very much in the public's interest to have the copyright retained
"
Neil Turkewitz
Recording Industry Association of America
Until now, many recordings that went out of copyright were by artists largely forgotten by today's CD-buyers - but the 50th anniversary of many important rock 'n' roll, opera and jazz recordings is approaching.
The Recording Industry Association of America (RIAA) says such imports are currently not allowed into the US, but press reports suggest they often find their way to shops.
Importing CDs of those recordings would amount to piracy, RIAA executive vice president international Neil Turkewitz told BBC News Online.
"You are now looking at more and more commercially viable recordings coming into the public domain in Europe, so I think the profile of this is likely to increase," he said.
European performers would begin to be hit by the "cultural implications and economic costs" of seeing their work go out of copyright, he said.
"Hopefully that will cause European policy-makers to rethink the terms."
Although the current EU rules may lead to cheaper CDs, the RIAA says music fans are better off in the long term if copyright is protected for longer.
"If you want to drive diversity and improve quality, then protection is the necessary element for promoting investment in those things," Mr Turkewitz said.
"I think it's very much in the public's interest to have the copyright retained."
EMI Classics, which has owned the copyright to Maria Callas recordings since they were made, has been forced into an alliance with independent label Marcal, which was the largest producer of bootleg live Callas recordings, the New York Times reported.
They joined forces so EMI Classics could keep a dominant position in the market for Callas - their biggest artist - the newspaper said.
The US music industry is already battling internet piracy and CD-copying, which it has blamed for a 9% slump in CD sales.