(Updates with details, background)
By Tim Hepher
BARCELONA, Sept 28 (Reuters) - A senior Airbus Group AIR.PA executive, Christian Scherer, is to be named as chief executive of Franco-Italian turboprop aircraft maker ATR, a person familiar with the matter said on Wednesday.
Scherer, who currently heads Airbus Group International, will replace Patrick de Castelbajac, who is leaving half way through his four-year mandate to return to Airbus, one of ATR's two shareholders, the source said, asking not to be named.
Scherer is expected to serve the full four-year term at the world's largest regional turboprop maker, whose top post usually alternates every four years between joint shareholders Airbus Group and Italy's Leonardo Finmeccanica LDOF.MI .
ATR declined to comment.
The appointment of Scherer, seen as one of the main architects of the successful A320neo Airbus jet programme as well as the launch of a new overseas Airbus assembly plant in Alabama, is expected to be announced in the coming weeks.
Industry sources say he will bring a staunchly commercial focus as the European turboprop maker, and its main rival Bombardier BBDb.TO of Canada, face volatile markets.
With $2 billion of turnover, ATR contributes steadily to both shareholders but there have been differences over strategy in recent years as Airbus blocked proposals for a new 90-seat turboprop that was viewed more favourably by Leonardo.
Longer term, there also remains uncertainty over its future shareholder structure, with Leonardo reported to be interested in buying out its French partner while Airbus Group would like to get hold of Leonardo's stake in missiles venture MBDA.
Scherer, an Airbus veteran whose engineer father was onboard the maiden flight of an Airbus jet over 40 years ago, has spent most of his career in the Airbus commercial jets arm including as strategy chief, before switching to defence and space sales followed by head of international operations at Airbus Group.
Despite only completing half his mandate, de Castelbajac had recently appeared ready to leave ATR following signs of friction with Italian shareholders, according to industry reports.
Usine Nouvelle reported last week he could land a senior role under Airbus planemaking chief Fabrice Bregier.
ATR predicts demand for 2,800 turboprop aircraft in the next 20 years, about two thirds of which would come from new routes and growth in countries like China and India.
Officials at rival Bombardier told the ISTAT Aviation conference in Barcelona that Iran could be a strong market for turboprops on domestic routes due to arduous airport conditions.