At the year’s midway point, domestic box office is trailing last year by roughly 9%. But overseas, 2011 is on par with 2010′s record-setting tally — and some studio estimates say the first half is up 6% over the same period last year.Both the domestic and overseas box office has seen a recent spurt paced by summer tentpoles including the latest “Pirates of the Caribbean” pic. “X-Men: First Class” also contributed — as, no doubt, will this weekend’s “Transformers” entry and the upcoming “Harry Potter” pic. Paramount’s third “Transformers” installment, “Dark of the Moon,” is outpacing its predecessor by 38% in its debut territories overseas. Overseas box office in May and June outstripped 2010 by a whopping 42%, according to some studio figures. A significant number of pics that opened late last year (e.g., “Tangled” and “Black Swan”) played well into 2011 thanks to staggered holiday releases, but the most impressive holdover was “The King’s Speech” at $226 million since Jan. 1. Otherwise there was little to brag about from the first few months of 2011. Of the year’s top 20 grossers internationally, only four bowed during the first quarter, down 50% from last year. They were 20th Century Fox’s “Rio,” Paramount’s “Rango” and Sony pair “The Green Hornet” and “Battle: Los Angeles.” The summer’s massive influx of day-and-date releases had some bizzers questioning whether overseas auds, who typically see fewer movies than Americans do, would turn out at plexes week after week. Case in point: Universal didn’t take any chances with “Fast Five,” releasing it a week before its U.S. launch in a few key overseas markets, including Australia, South Korea and the U.K. That strategy was employed to maneuver around Paramount’s “Thor,” which went a week later in 54 markets. “Fast Five” went head to head with “Thor” the second weekend in May, however, with the former ultimately winning that frame. “Fast Five” has cumed $388 million internationally; “Thor,” around $225 million. Other summer pics lifting 2011 overseas totals include Warner Bros.’ “The Hangover Part II,” now the biggest R-rated comedy at the global box office with $529 million (pic’s international take is $284 million). Since American comedies don’t traditionally travel well overseas, “Hangover II” reps one of the summer’s bigger surprises, though not a complete shocker given the popularity of the original “Hangover.” More surprising were “The King’s Speech” and “Black Swan.” “King’s Speech,” with a cume of $274 million, had been expected to play boffo in English-speaking territories, particularly in the U.K., but its longevity can be chalked up to how well it played everywhere else. The same could be argued for “Black Swan”; Fox Intl. strung out the pic’s overseas release through the end of February (pic launched Dec. 3 in the U.S.) for an international cume of $220 million. B.O. pundits expect the remaining summer lineup to keep the ball rolling internationally, most notably, Warners’ “Harry Potter and the Deathly Hallows: Part 2.” The final “Harry Potter” pic goes out virtually everywhere the weekend of July 15. Since it is the finale of the eight-film series, and the first in 3D, some bizzers are expecting it to conjure ginormous (and possibly record-breaking) tallies all around the globe.