Airbus Group (AIR.PA) on Tuesday announced the resignation of the no.2 at its planemaking unit, Chief Operating Officer Gunter Butschek, after 2-1/2 years in the role.

Butschek will be succeeded by Tom Williams, executive vice president in charge of Airbus programs, who will in turn be replaced by A350 program chief Didier Evrard, who has completed development of the company's newest wide-body jet.

In a letter to staff, Fabrice Bregier, chief executive of the main planemaking subsidiary of Airbus, paid tribute to Butschek and said the former Mercedes (DAIGn.DE) executive had "decided to pursue new opportunities outside of the company".

Airbus Group CEO Tom Enders said in a statement following a board meeting he regretted Butschek's resignation.

Butschek joined Airbus in March 2011 and became chief operating officer of the main planemaking business in June the following year.

He was credited with expanding the use of car industry techniques in Airbus, a trend expected to continue under procurement chief Klaus Richter, a former BMW (BMWG.DE) executive who remains in charge of procurement for the group but is promoted with Williams to the group executive committee.

Aerospace industry sources say Butschek had not established himself as part of the planemaker's inner circle. A person close to him said he had left of his own volition and analysts said there was no connection between the resignation and a sharp drop in shares following an investor meeting last week. [ID:nL6N0TV2D1]

Butschek was not available for comment.

Williams, 62, is an aerospace veteran who began on the shop floor with Rolls-Royce (RR.L) and held senior roles on the Eurofighter with BAE Systems (BAES.L), before transferring in 2000 to Airbus, in which BAE then had a stake.

He has a reputation as a tough but effective troubleshooter and led the planemaker's response to the discovery of cracks in components of the wings of the A380 superjumbo jets in 2012.

The executive, who began as an apprentice in his native Scotland, once told Reuters: "There is the official factory floor and the real factory floor; you have to know both."

The changes mean the A350, due to be delivered to Qatar Airways next week, will be reintegrated into the rest of Airbus as it shifts towards a production phase.

Given the risks of building its first mainly carbon-composite airliner, and anxious not to repeat mistakes by rival Boeing (BA.N) in producing the 787 Dreamliner, Airbus had placed the project under a separate team led by Evrard, a Frenchman who successfully ran Europe's Storm Shadow cruise missile project.