The Avengers

Joss Whedon’s superhero pic continues to do bang-up business overseas, where its total through Monday was already $218 million; the tentpole opens in North America at midnight Thursday.

Disney and Marvel Studios appear to have a runaway hit on their hands.

The Avengers, which only began rolling out at the international box office late last week, is easily on track to become the most successful title produced in-house by Marvel Studios, besting the $623 million worldwide gross of 2010’s Iron Man 2.

Directed by Joss Whedon, Avengers is doing massive business at the international box office, earning $218 million in its first six days through Monday and breaking records across the globe. And the 3D pic, which unites many of Marvel’s marquee superheroes, could enjoy weekend-like business Tuesday because of the May Day holiday in many foreign markets.

At this pace, Avengers’ foreign gross likely will grow to $350 million-$400 million by Sunday, boosted by its debut in Russia and China this weekend.

Avengers opens at midnight Thursday in North America, where it’s widely expected to debut north of $150 million, based on the strength of prerelease tracking. Bullish box office observers believe Avengers could finish the weekend with a global gross well north of $500 million, if not closer to $600 million.

The superhero tentpole is the first Marvel Studios film marketed and distributed by Disney following the company’s acquisition of Marvel.

Last summer, Marvel’s Thor grossed $449.3 million worldwide, while Captain America: The First Avenger earned $368.6 million. The first Iron Man earned $585 million globally in 2008; all three characters are featured in Avengers.