NEW YORK  —  50 Cent believes his new album will outsell Kanye West's upcoming disc, and he's betting his solo career on it. Both 50 Cent and West have albums due out Sept. 11. 50 Cent, who has sold better than West, has been riled by forecasts that sales of West's "Graduation" could rival those for his "Curtis" CD.

"Let's raise the stakes," the 31-year-old rapper told hip-hop Web site SOHH.com in an interview posted Friday. "If Kanye West sells more records than 50 Cent on September 11, I'll no longer write music. I'll write music and work with my other artists, but I won't put out anymore solo albums."

An e-mail sent to West's publicist wasn't immediately returned Friday.

50 Cent, whose real name is Curtis James Jackson, has been publicly disparaging of West before. In 2005, he suggested the 29-year-old rapper's popularity was only possible because of 50's own success.

But they recently collaborated in the studio. Their work, though, isn't scheduled to appear on either new album.

50 Cent's last full-length solo album, "The Massacre," was the best-selling disc of 2005 and sold more than 1.14 million copies in its first week of release. The same year, West's "Late Registration" opened by selling more than 860,000 copies in its first week.