Paramount Pictures has become the first studio this year to cross $1bn at the domestic box office on the back of Iron Man 2’s $306.9m theatrical run.

This marks the fourth year in a row that Paramount has been the first studio to reach the milestone. The studio crossed on June 28 and currently ranks top in market share with four of the ten biggest releases of the year-to-date.

Aside from Iron Man 2 (pictured) the key drivers were Shutter Island on $128m, and the DreamWorks Animation duo of How To Train Your Dragon and Shrek Forever After on $215.4m and $229.4m and counting, respectively.

“This milestone reflects the hard work of so many people,” Paramount chairman and CEO Brad Grey said. “I especially want to thank Rob Moore, Frederick Huntsberry, and Adam Goodman. We are all so proud of our teams, how they have worked together as well as with our partners.

“This commitment, coupled with the terrific creative talent we are in business with – Michael Bay, JJ Abrams, Martin Scorsese, Jon Favreau, Jeffrey Katzenberg and his DreamWorks Animation – have made these results possible.”

“We are all incredibly gratified to have achieved this again in 2010 and for our fourth year running,” vice-chairman Rob Moore said. “We have released six films in the past four years which have surpassed $300m domestically.”

Upcoming releases include M Night Shyamalan’s The Last Airbender in 3D on July 1, Grease Sing-A-Long on July 8, and Jay Roach’s Dinner For Schmucks on July 30.