Shutter Island is well on its way to $100m as a $22.2m number one hold boosted Paramount’s mystery thriller to $75.1m after two weekends.

Meanwhile Avatar became the first film in North American box office history to cross $700m as a further $14m from 2,456 theatres brought the latest tally to $706.9m. The film slipped one place to number four and fell a mere 14% in its eleventh weekend.

Elsewhere there were two strong launches in second and third places by Warner Bros’ action comedy Cop Out and Overtures’ George A Romero horror remake The Crazies.

Returning to Shutter Island, Martin Scorsese’s film headlining Leonardo DiCaprio now looks odds-on to become the director’s biggest commercial hit as it races toward the $133.3m high-water mark set by 2006’s The Departed.

Cop Outstars Bruce Willis and Tracy Morgan and arrived in second place on $18.6m, while The Crazies, which stars Timothy Olyphant and Radha Mitchell, opened third on $16.5m in a good launch for Overture.

Warner Bros’ romantic comedy Valentine’s Day in sixth place crossed $100m in its third weekend as a further $9.5m raised the running total to $100.4m. Fox’s Percy Jackson & The Olympians: The Lightning Thief in fifth place added $9.8m for $71.2m after the same amount of time.

Outside the top ten Sony Pictures Classics scored a notable launch with A Prophet on a formidable $170,000 from only nine theatres. The film was the big winner at the Cesars in France over the weekend and walked away with ten trophies including best picture, director for Jacques Audiard and star for Tahar Rahim.

Next weekend’s wide releases are Disney’s 3D fantasy Alice In Wonderland from Tim Burton and starring Johnny Depp, Anne Hathaway, Helena Bonham Carter and Mia Wasikowska; and Overture Film’s crime thriller and Sundance 2009 hit Brooklyn’s Finest starring Richard Gere, Ethan Hawke and Don Cheadle.

Estimated Top 10 North America Feb 26-28 2010

Film (Dist) / Est wkd gross / Est total to date

1 (1) Shutter Island(Paramount) PPI $22.2m $75.1m

2 (-) Cop Out (Warner Bros) WBPI $18.6m –

3 (-) The Crazies (Overture) Paramount Vantage Int’l $16.5m –

4 (3) Avatar(Fox) Fox Int’l $14m $706.9m

5 (4) Percy Jackson & The Olympians: The Lightning Thief (Fox) Fox Int’l $9.8m $71.2m

6 (2) Valentine’s Day (Warner Bros) WBPI $9.5m $100.4m

7 (6) Dear John (Screen Gems) Lionsgate $5m $72.6m

8 (5) The Wolfman(Universal) UPI $4.1m $57.2m

9 (7) Tooth Fairy (Fox) Fox Int’l $3.5m $53.9m

(8) Crazy Heart (Fox Searchlight) SPRI $2.5m $25.1m