Updated

Eminem's (search) new album debuted atop the charts, following a decision by the rapper's record label to move up the album's sale date amid piracy concerns.

"Encore" (search) sold 711,000 copies between Friday and Sunday, according to Nielsen SoundScan. The media tracking firm's figures cover all U.S. album sales for the week that ended Sunday.

Behind "Encore" were three compilations by country music acts Shania Twain, Toby Keith and pop diva Britney Spears. Twain's "Greatest Hits" sold 530,000 copies, while fans bought 435,000 copies of Keith's "Greatest Hits 2." Spears' "Greatest Hits: My Prerogative" sold 255,000.

"Encore" was originally slated to be released Tuesday, but Eminem's label, Universal Music Group's Aftermath/Interscope, decided to move up the sale date after tracks began turning up on Internet file-sharing networks.

The release date of Eminem's previous album, 2002's "The Eminem Show," was released four days before its original sale date, selling 285,000 copies in three days. A week later, it sold 1.3 million copies.

Record labels put a premium on racking up strong sales in the first week. But last-minute changes in release dates can be dicey, because advertising and promotion deals often hinge on the timing, which can be designated months or weeks in advance.

That hasn't kept record labels from altering the release date of recordings by several high-profile acts in recent weeks.

Universal's Geffen label moved up the release of rapper Snoop Dogg's latest album, "R&G (Rhythm & Gangsta): The Masterpiece," to Tuesday, a full week ahead of the original Nov. 23 sale date.

Sony BMG Entertainment's Columbia Records label also opted to release the new album by pop trio Destiny's Child a day ahead of schedule, citing worries over piracy.