RollingStone.com is reporting that METALLICA have hunkered down in a San Francisco studio, breaking ground on their ninth studio disc, with producer Rick Rubin (SYSTEM OF A DOWN, AUDIOSLAVE, SLAYER). After opening two shows for the ROLLING STONES last November, 'TALLICA got the itch to stitch together a new album. "We've been writing, jamming, hanging for about two months," drummer Lars Ulrich tells RollingStone.com. "Right now it's me, James [Hetfield] and Rob [Trujillo] — Kirk [Hammett] shows up once in a while." On their last album, "St. Anger", the band wrote and recorded simultaneously; this time, they'll first spend about six months composing brain-rattling riffs and mining recordings of pre-show jams from the "St. Anger" tour for material. The boys are currently booking some one-off summer dates to break the monotony. "Japan, South Africa, Bumfuck — we'll play anywhere," says Lars. "I'll draw the line at bar mitzvahs, but backyard keggers for sure."As previously reported, sources close to METALLICA recently told Launch that the band will not play any U.S. shows this summer, despite speculation that the group would either headline Ozzfest or mount their own stadium tour. While METALLICA are playing three concerts in South Africa later this month and have a string of European festival appearances lined up for June, their schedule has been empty for the rest of the summer, leading to rumors of some sort of U.S. jaunt. However, the sources say that the band will enter the studio in July with producer Rick Rubin to begin recording its ninth studio album. METALLICA will make its South African debut on March 18, March 21 and March 25 as part of a massive music festival called the Coca-Cola Colab Mix.