(Reuters) - Boeing has discovered a problem related to the aft fuselage of its 787 Dreamliner planes and is making repairs that will not affect production of the aircraft, the company said in an emailed statement on Sunday.

The 787 Dreamliner is a light-weight, fuel-efficient, carbon-composite aircraft. It was three years behind its development schedule but finally entered service last year.

"Boeing has found that incorrect shimming was performed on support structure on the aft fuselage of some 787s," Boeing spokesman Scott Lefeber said.

Lefeber added, "we do not expect that it will affect our planned product rate increases," and that there are no short-term safety concerns.

Boeing aims to ramp up monthly production on the airplane to 10 by the end of 2013. Some experts believe the target rate is too ambitious, but Boeing is standing by it.

Lefeber declined to identify how many aircraft were affected.

The news was first reported by the aviation website Flightglobal.

(Reporting By Liana B. Baker in New York and Kyle Peterson in Chicago; Editing by Tim Dobbyn)