Dan Murphy, Alliant Techsystems’ [ATK] chairman and CEO for the past six years, yesterday said he was leaving the company to “address family matters” and the company’s Board of Directors said he will be succeeded immediately by Chief Financial Officer (CFO) John Shroyer in the interim and has launched a search for a permanent chief.

ATK expects to have a successor to Murphy in place no later than the first quarter of 2010.

“I am leaving the company to address family matters that require my personal attention,” Murphy said in a statement. “This is an extraordinary company with committed and hard working employees, and I am confident that ATK will continue to deliver solid results as it maintains and builds on its strong competitive position in the months and years ahead.”

Murphy, ATK’s longest running CEO, will be available to assist ATK with the leadership transition until his retirement in March 2010 when his current contract expires. The company also announced that its lead board member, Ronald Fogleman, a former Air Force Chief of Staff in the 1990s and member of the board for over five years, has been appointed chairman effective immediately.

ATK’s board has hired a nationally known executive search firm to find replacement for Murphy. ATK said it will consider both internal and external candidates.

Murphy joined ATK in 2001 as head of its Tactical Systems Group after a 30-year career with the Navy where he retired as a vice admiral. In 2002 Murphy became president of the company’s newly created Precision Systems Group and in the fall of 2003 became CEO, succeeding Paul Miller, who had led the company since 1999. Murphy became ATK’s chairman in 2005.

During Miller’s time as ATK’s CEO, he greatly expanded its propulsion business through key acquisitions and also laid the foundation for growth in new areas such as a systems integrator of precision weapons and moving beyond being a supplier of ammunition to the United States military by expanding into law enforcement and commercial markets. But it was up to Murphy to implement the new growth avenues ATK was charting, and eventually to create new business lanes.

Under Murphy, ATK began to compete head-on with heavyweights such as Lockheed Martin [LMT] and Raytheon [RTN] in the precision munitions arena, offering customers lower cost solutions. This strategy has taken a while to bear fruit, but ATK is now in low-rate production of the Advanced Anti-Radiation Guided Missile. The company is also competing for business on a precision mortar program and another project to equip artillery shells with a guidance package to dramatically improve their accuracy.

In the past few years ATK has also assumed a market leadership position in the civil and commercial ammunition markets, and moved into international ammunition markets. ATK has also established a foothold in composite aerostructures, first in the F-35 Joint Strike Fighter program and now in the Airbus 350 passenger plane currently in development.

With Murphy at the helm, ATK also made a series of acquisitions in the space and propulsion areas, giving it capabilities to produce small satellites and play a larger role in the construction of big satellites, and also to be able to offer government customers next-generation capabilities related to hypersonic flight. Moreover, through its various capabilities in space systems, ATK plans to compete for business with government customers seeking a relatively quick ability to launch urgent payloads into space.

ATK’s sales have more than doubled during Murphy’s tenure, from a little over $2 billion in 2003, with $4.8 billion targeted in the current fiscal year. The company posted its second quarter financial results last night and will host an analyst call this morning.

As for how ATK will be moving forward without Murphy, a spokesman said that the company’s “character” has been established.

“ATK’s unique brand of affordable innovation matured under Dan’s leadership and is now well engrained in the company, it is who we are,” company spokesman Brian Cullin told Defense Daily. “We are confident that character will shape our strategy, operations, and growth for the future.”

ATK’s operational leaders remain in their current roles. They are: John Cronin, president of Mission Systems; Mark DeYoung, Armament Systems; and Blake Larson, Space Systems.

Shroyer, who will remain as CFO while he takes on the CEO duties temporarily, has been with ATK for 23 years in a variety of management and operational roles. Prior to becoming CFO in 2006, he was the company’s vice president of operations. Before that he was vice president and general manager of Ordnance Systems and between 2002 and 2004 was president of Tactical Systems.

Fogleman has served on several boards, including non-executive chairman of World Airways from 2003 to 2007. He is currently a director of AAR Corp. [AIR], the Alpha Security Group Corp., and Atlantic Inertial Systems.