UPDATE 3-Rugby-All Blacks drop cornerstone prop Franks for World Cup

* Franks had played last two World Cup tournaments

* Retallick in despite dislocated shoulder

* Mo'unga also confirmed after shoulder injury (Adds quotes)

By Greg Stutchbury

WELLINGTON, Aug 28 (Reuters) - All Blacks coach Steve Hansen dropped a World Cup bombshell on Wednesday by leaving Owen Franks out of his squad and selecting more mobile props as he signalled an intent to play an up-tempo game in Japan.

Franks has been a cornerstone of the All Blacks scrum since he made his debut as a raw 21-year-old and was a key member of the squads that won the last two World Cups.

The 31-year-old tighthead, who has played 108 tests, suffered a shoulder injury that kept him out of much of Super Rugby this year but returned to the national side for the Rugby Championship.

He was dropped for the Bledisloe Cup clash against Australia at Eden Park, however, and Nepo Laulala seized his opportunity to usurp Franks with an impressive scrummaging display and strong work around the field.

"Owen has been one of the great All Blacks, but we believe that the game requires us to have big, mobile number ones and number threes," Hansen told reporters at Eden Park after he named the squad.

"In this case we think the other guys we have named are more (mobile) and we had to make a tough decision."

Hansen said he had delivered the decision to Franks, who was "disappointed but very respectful". Franks is joining English club Northampton after the World Cup.

Lock Brodie Retallick was included in the 31-man squad despite suffering a dislocated shoulder against South Africa last month, as was midfield back Ryan Crotty, who has been out of action for two months with a broken thumb.

Hansen told reporters in Auckland that he did not expect Retallick to play in the pool phase. Patrick Tuipulotu was named as the fourth lock with Retallick, Sam Whitelock and Scott Barrett.

Rookie loose forward Luke Jacobson was also included after Liam Squire made himself unavailable earlier this year.

Hansen had left the door open for Squire if he made himself available but said on Wednesday the burly blindside flanker had agreed to a callup if the squad had injury issues in Japan.

Rookie wingers George Bridge and Sevu Reece were also selected after strong performances in the 36-0 victory over Australia when Hansen dropped veteran Ben Smith and Rieko Ioane after some sub-par performances.

Both Smith, who is leaving for France after the tournament, and Ioane were named along with the versatile Jordie Barrett, who can play across the backline.

Flyhalf Richie Mo'unga, who injured his shoulder against the Wallabies, was given the all clear and is expected to resume his dual playmaking role with Beauden Barrett at the tournament.

The pair are the only flyhalves named in the squad, although Barrett has played fullback under the dual playmaker system.

Hansen also said that Crotty, Jordie Barrett and scrumhalf TJ Perenara could cover flyhalf in an emergency.

The Barretts are the first trio of brothers to be included in a New Zealand World Cup squad.

The All Blacks open their campaign on Sept. 21 against South Africa in Yokohama, with the loser of the Pool B clash likely to face Ireland in the quarter-finals.

Backs - Ben Smith, Rieko Ioane, Jordie Barrett, George Bridge, Sevu Reece, Ryan Crotty, Sonny Bill Williams, Jack Goodhue, Anton Lienert-Brown, Beauden Barrett, Richie Mo'unga, Aaron Smith, TJ Perenara, Brad Weber

Forwards - Kieran Read (captain), Ardie Savea, Sam Cane, Matt Todd, Luke Jacobson, Brodie Retallick, Sam Whitelock, Scott Barrett, Patrick Tuipulotu, Joe Moody, Nepo Laulala, Ofa Tuungafasi, Angus Ta'avao, Atu Moli, Codie Taylor, Dane Coles, Liam Coltman

(Reporting by Greg Stutchbury in Wellington; Editing by Nick Mulvenney/Peter Rutherford)