"Avatar" continued to storm the box office on Sunday, passing the one-billion-dollar mark in worldwide revenues, according to newly-released figures.

The Fox Studios movie is again this weekend box office champ with 68.3 million dollars in projected sales, Hollywood.com estimated.

The movie, the story of an ex-Marine who finds himself thrust into hostilities on an alien planet filled with exotic life forms, has grossed US$352.1 million in the United States and Canada, and US$670.2 million overseas.

Analyst Paul Dergerabedian said the film is the highest- grossing IMAX release ever, with US$66.4 million in 3-D round-screen sales.

"Sherlock Holmes" was in second place, with US$38.4 million in estimated holiday weekend sales. The Warner Bros. release is projected to take in US$140.7 million in its first two weeks of release.

"Alvin And the Chipmunks: The Squeakquel" is in third, with a predicted US$36.6 million in weekend sales for a two-week total of US$157.3 million.

Rounding out the top 10 weekend films for domestic takes, as estimated by Hollywood.com, are:

-- "It's Complicated," Universal, US$18.7 million this weekend, US$59. 1 million over two weeks;

-- "The Blind Side," Warner Bros, US$12.7 million this weekend, US$209 million over seven weeks;

-- "Up In The Air," Paramount, US$11.4 million this weekend, US$45 million over five weeks;

-- "The Princess And The Frog," Disney, US$10 million this weekend, US$86 million over six weeks;

-- "Did You Hear About The Morgans?," Sony, US$5.2 million this weekend, US$25.6 million over three weeks;

-- "Nine," Weinstein Co., US$4.3 million this weekend, US$14 million over three weeks; and

-- "Invictus," Warner Bros., US$4.1 million this weekend, US$30.8 million over eight weeks.