Rapper T.I. has posted the biggest sales week of the year, selling 522,000 copies of “King” (Grand Hustle/Atlantic) in its opening sesh, according to Nielsen SoundScan.

“King” scored the best sales tally for an Atlantic Records album in the 15-year history of SoundScan. “King,” T.I.’s third disc and second chart-topper, saw the best sales week since Mary J. Blige’s “The Breakthrough” debuted with sales of 727,000 and Jamie Foxx’s “Unpredictable” hit 598,000 in the week before Christmas. In the past 16 months, only albums by the Game, 50 Cent and Kanye West have posted better opening sales weeks.

T.I. also stars in Warner Bros. pic “ATL,” which opened Friday and grossed $11.5 million in its opening stanza to take No. 3 on the B.O. chart. His single “What You Know” is the top-ranked streaming track at MySpace.com and No. 1 ringtone.

With T.I. and James Blunt’s “Back to Bedlam” leading the way, Warner Music Group has enjoyed an incredibly strong first quarter. Label group boasts a market share of nearly 25% for the quarter, behind only Universal Music Group at 31.6% and ahead of Sony BMG’s 23.6%. EMI has 8%, and the indies are just under 12%.

“King” is one of five debuts in the top 10, which had a bonus shakeup as Shakira’s English-language “Oral Fixation Vol. 2” sashayed its way up 92 slots to No. 6.

Tim McGraw’s “Greatest Hits Vol. 2” (Curb) sold 242,000 copies to land at No. 2. Vol. 1 sold 64,000 more copies in its first week six years ago, debuting at No. 7.

Ghostface Killah, meanwhile, nearly doubled the sales of his last album, 2004’s “The Pretty Tony Album,” selling 110,000 copies of “Fishscale” (Def Jam). The New York rapper, a member of the Wu Tang Clan, took the No. 4 slot, selling 3,000 more copies than Rob Zombie’s “Educated Horses” (Geffen).

Zombie matched his highest chart position, No. 5, as “Horses” sold 107,000. His other No. 5, “Hellbilly Deluxe,” sold 120,000 units in its first week.

Atreyu’s “Deathgrip on Yesterday” (Victory) sold 69,000 copies to open at No. 9. It is the second Victory Records release in March to score a career-best sales week; Hawthorne Heights’ “If Only You Were Lonely” was the first.

The Yeah Yeah Yeahs missed the top 10 by 2,000 album sales, opening at No. 11 with “Show Your Bones.” Their second Interscope release sold 56,000 copies.

Following Shakira’s performance last week on “American Idol,” “Oral Fixation Vol. 2” (Epic), in its 18th week on the charts, shot to No. 6 on sales of 81,000 copies. Movement — disc was at No. 172 two weeks ago — was also driven by the hit single “Hips Don’t Lie,” featuring Wyclef Jean. Song’s two videos, one of her and one of fans shaking their hips, have caught fire on Internet sites such as Yahoo! Music. Shakira also appeared on “Live With Regis and Kelly,” Ellen DeGeneres’ gabfest and CBS’ “The Early Show.”

The only other debut in the top 100 was Rammstein’s “Rosenrot” (Universal), which sold 21,000 copies and opened at No. 47.

For the first quarter of 2006, sales are a smidge ahead of 2005. Nielsen SoundScan has reported 140.4 million albums sold plus 144 million tracks sold. Using the Track Equivalent Albums formula (10 downloaded singles equals an album sale), the tally is at 154.8 million.