UPDATE 2-Boeing gets grip on 787 supply chain with upsized jumbos

* Planemaker on path to build 10 a month - executive

* Supply chain includes 325 suppliers, 5,000 factories

* "We made mistakes along the way" - VP for supply

* Japanese supplier says bottleneck risk remains

(Adds comment, details)

NAGOYA, Japan, Oct 10 (Reuters) - A Boeing Coofficial said the planemaker has its sprawling global supplychain under control for its lightweight Dreamliner jet and plansto ratchet up production, a jump in output a Japanese suppliersaid could expose new supply bottlenecks.

Boeing has outfitted at least four 747 freighters with widerfuselages, dubbed "Dreamlifters", to gather parts from aroundthe world for its 787 jet that are then assembled at plants inWashington and North Carolina in the United States.

The company is trying to make up for earlier delays causedin part by the difficulties in managing 325 suppliers buildingparts for the 787 at 5,000 factories worldwide.

Boeing now makes three and a half of the carbon-compositejets per month. It plans to raise output to five a month by theend of the year and raise it to 10 per month by the end of 2013.

The new target was described on Wednesday as a "verydifficult target" by Jeffrey Luckey, the Boeing executive incharge of the plane's supply management.

"We made mistakes along the way. We are currently on path toachieve 10 a month," Luckey said during a presentation at theJapan Aerospace International Exhibition in Nagoya. "We knowwhen we are going to pick them up and drop them off," Luckeysaid. "We lost visibility in the supply chain."

The 787 jet is the most outsourced in Boeing's history andJapanese companies such as Fuji Heavy Industries Ltdand Mitsubishi Heavy Industries Ltd account for morethan a third of its components, including the first wings builtoutside the United States.

At a Fuji Heavy plant near the show venue in Nagoya, factorymanager Hiroyuki Ishikawa is preparing a new production line tobuild wing-boxes that connect the 787's wings to the fuselage.The factory is the sole supplier of the critical component,which is about the size of a small house.

While expressing confidence that his plant could match theplanned acceleration in 787 output in the United States, thehike in production Ishikawa noted, "could expose bottlenecks" inthe availability of parts from lower-tier suppliers.

Fuji Heavy's aerospace business, which Boeing named assupplier of the year in 2011, buys components from about 160companies in Japan and overseas.

The 787 wing-boxes coming out of Ishikawa's facility arecarried to the United States on the upsized Dreamlifters.Wing-boxes for Boeing's 777 jet the company fabricates at a linenext door are shipped by sea.

Boeing's Dreamliner, which boast fuel savings of 20 percentcompared with its predecessor, the 767, has so far won 824orders, with around 60 delivered. The plane's list prices rangefrom $200 million to $240 million, but most sales arediscounted.

Japan's All Nippon Airways was the launch customerfor the 787, ordering 66 partially made-in-Japan aircraft, whichit has put at the center of its fleet planning.

(Reporting by Tim Kelly; Editing by Matt Driskill)