LOS ANGELES (Reuters) - Buoyed by the blockbuster success of “Iron Man” over the weekend, Marvel Studios on Monday announced plans for a string of superhero properties, including an “Iron Man” sequel set for April 2010.

“Iron Man 2” will be followed in June 2010 by the big-screen adaptation of another of Marvel’s popular comic book characters, “Thor,” the mighty, hammer-wielding hero based on the Nordic god of the same name, the company said.

“Captain America” and “The Avengers” are next in line for the summer of 2011.

The nearly $99 million opening weekend of “Iron Man,” Marvel’s first fully self-financed production, gave Hollywood’s summer movie season a solid start and set the stage for a robust earnings report from the studio’s corporate parent, Marvel Entertainment Inc.

Drawing largely favorable reviews, “Iron Man” stars Robert Downey Jr. as billionaire industrialist and playboy Tony Stark, who wrestles with a mid-life crisis as he invents a high-tech suit of armor that transforms him into a superhero.

Kevin Feige, head of production for Marvel Studios, said Downey would return in the sequel as part of his three-picture deal for the franchise. Feige said the gifted actor deserved much of the credit for the film’s broad appeal.

“It’s great to see a sold-out audience that you know is made up of comic book fans and people who had never read an ‘Iron Man’ comic in their life,” he said.

Marvel shares soared nearly 10 percent on Monday as the company reported first-quarter profits above market estimates and raised its 2008 financial outlook.

Costing about $150 million to make, “Iron Man” was distributed by Viacom Inc.’s Paramount Pictures studio, which footed the $75 million marketing bill for the movie and received a flat fee for its efforts.

Cast member Robert Downey Jr. and his wife Susan Downey attend the premiere of "Iron Man" at the Grauman Chinese Theatre in Hollywood, California April 30, 2008. REUTERS/Mario Anzuoni

The same arrangement will apply for “Iron Man 2” and an upcoming film based on “Captain America,” the iconic crime-fighter created in 1941.

That film, now titled “The First Avenger: Captain America,” is slated for release in May 2011, to be followed by “The Avengers,” based on a team of Marvel heroes that has included Iron Man, Thor and Captain America, in July of that year.

‘IRON MAN’ PROVES BOX OFFICE METTLE

An adaptation of Marvel’s “Ant-Man” character also is in development. But with the coveted summer movie release dates for 2009 already well booked by other studios, Marvel has no self-produced films scheduled to open next year.

Instead, the company said it would “focus its attention on maximizing the success of an ‘Iron Man’ sequel and the launch of ‘Thor’ in the summer of 2010.”

The final Friday-through-Sunday tally for “Iron Man” came to $98.6 million, down slightly from the $100 million-plus studio estimate reported on Sunday.

But even without an additional $3.5 million grossed from Thursday “previews,” the film easily exceeded the debut weekends of sequels to two other hit Marvel franchises -- “Spider-Man 2” and “X2: X-Men United” ($88.2 million and $85.6 million, respectively).

“Iron Man” also ranks as the second-biggest domestic debut ever for a non-sequel movie, a record set by the first “Spider-Man” with $114.8 million in May 2002. “Spider-Man 3” stands as the top movie opening of all time -- $151 million in U.S. and Canadian ticket sales its first weekend in May 2007.

“Iron Man” also proved its international mettle, grossing nearly $97 million from overseas openings in 57 foreign markets and claiming the No. 1 box office spot in most of those.

Although the studio has no movies in the works for release next year, three animated TV series are set to debut in 2008 based on Marvel’s Iron Man, Hulk and X-Men titles.

The very next Marvel film slated for release is “The Incredible Hulk,” headed to theaters next month as a remake based on the oversized, green brute originally brought to the big screen in a 2003 commercial dud directed by Ang Lee.

Universal Pictures, an NBC Universal unit controlled by General Electric Co, will distribute the new film, as it did the first “Hulk.”

Reuters/Nielsen