Leer’s retirement is effective as of April 26, the same day as the company’s annual shareholders meeting.
He will remain the producer’s board chairman.
The executive was initially elected the CEO of Arch predecessor Arch Mineral Corporation in 1992.
When Arch Coal was established five years later in 1997, he again became its CEO.
Under the leadership of Leer, Arch grew from a regional coal entity with 20 million tons in sales to the fourth-largest coal producer in the world, with 2011 volumes that exceeded 155Mt.
“The board, John and I have been planning for this transition since John was elected to the board in 2006 and I am confident that he is the ideal person to lead Arch forward at this time of tremendous growth and change in global energy markets," Leer said.
“He has spearheaded our recent growth initiatives, led Arch's ongoing efforts to expand sales into the international arena and solidified our position as the industry leader in safety and environmental stewardship.
“I have no doubt that Arch Coal will build upon its record of achievement and success under John's strong leadership.”
Eaves, a graduate of the University of Kentucky and Harvard University, joined the company in 1987 after working in marketing seats for Diamond Shamrock and Natomas Coal.
He was elected senior vice-president of marketing and president of Arch Coal Sales in 1997 and in 2000 was tapped to be Arch Coal senior vice-president of marketing.
Two years later, Eaves accepted the elected seat of executive vice-president and COO and has served as president and COO of Arch Coal since 2006.
“Arch is exceptionally well-positioned to capitalize on the rapid growth in energy demand around the world and we will remain sharply focused on expanding our participation in global coal markets even as we continue to meet the need for secure and affordable energy here at home,” Eaves said.
“At the same time, we will continue to be guided by the three core values that have defined Arch Coal since its formation: safety excellence, environmental stewardship and strong financial returns.
“I look forward to the challenge of building on the great legacy of growth and success that Arch has achieved under Steve's leadership during the past 20 years.”