PARIS/BERLIN (Reuters) - An oil leak that grounded an Airbus (>> Airbus Group) A400M military plane with a German government minister on board does not point to a fundamental new problem with the West's largest turboprop engines, three sources close to the matter said.

Last week's breakdown was on a trip that was meant to showcase the aircraft's capabilities as Airbus seeks to win back confidence in the troubled A400M project from its largest purchasing nation.

German military officials initially said the leak appeared to be linked to the hydraulic system used to adjust the turbine blades in one of the four powerful A400M engines.

However, two of the three sources said the leak had been found between the propellers and the nacelle, or engine housing, which are part of the power system but not components of the engine itself.

"It doesn’t look like it came from the core of the engine," the third source said.

The German air force declined to comment.

If confirmed, the findings are likely to ease concerns over fresh delays in the 20 billion euro (16.96 billion pounds) project, which is already years behind schedule and heavily over budget.

However, the breakdown represents a public relations blow for Airbus, which is still grappling with previous problems that led to write-off amounting to more than 5 billion euros.

Defense Minister Ursula von der Leyen was forced to switch planes after visiting troops in Lithuania in what the ministry described as a "very aggravating" incident.

Problems with the engines, including software and an Italian-built gear component, contributed to years of delays and cost overruns in Europe's largest multinational defense project.

A German military source familiar with the program said last week that the latest incident appeared to involve a routine and relatively minor technical problem.

The propellers are made by France's Ratier-Figeac on behalf of Airbus, which supplies the nacelle.

The main part of the engine is supplied by a four-nation consortium led by Britain's Rolls-Royce (>> Rolls-Royce Holding PLC) and France's Safran (>> SAFRAN).

Airbus reiterated that it is doing what it can to support the investigation.

A spokesman declined to comment in detail on the incident, saying the investigation is being handled by the German air force. The aircraft was flown to a German air base late last week.

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(Reporting by Tim Hepher and Andrea Shalal; Editing by David Goodman)

Stocks treated in this article : Airbus Group, SAFRAN, MTU Aero Engines AG, Rolls-Royce Holding PLC