American AgCredit, Sonoma County's largest financial institution, on Thursday announced the retirement of longtime CEO Ron Carli and the promotion of his top manager, Byron Enix.

Enix, executive vice president and chief operating officer, will become president and CEO on Jan. 1. He came to American AgCredit in 2010 and has worked 29 years in the nation's farm credit system.

Carli, who is one of the longest-serving CEOs in that system, will retire on Jan. 31. The Cotati farm boy and former high school ag teacher has spent 35 years in the county working for associations that grew into American AgCredit, the nation's sixth-largest farm credit cooperative.

"Ron's been the leader that helped build this organization into the size and scale that it is today," Enix said Thursday.

The association has $6 billion in assets and more than 400 employees, including over 100 in Santa Rosa. It operates 33 branches in six states and has acquired five other farm cooperatives since 2000.

Enix grew up in Wichita, Kan., graduated in 1984 from Oklahoma State University and began his career as a loan officer in a federal land bank in Vinita, Okla.

The association's staff members believe in their work, Enix said, and they will continue to work for the "continuous expansion in the footprint of American AgCredit."

"We have a mission to serve farmers and ranchers with a dependable source of capital, whether that's good times in agriculture or bad times," he said.

The association is owned by roughly 7,000 shareholders, each a borrower in agriculture who purchased a single share of stock for $1,000.

Tim Tesconi, interim manager of the Sonoma County Farm Bureau, said under Carli's leadership American AgCredit became an important supporter of such agriculture groups as the Farm Bureau, the county fair, 4-H and FFA.

The cooperative was known for taking its earnings and "investing it back into the community to strengthen agriculture," Tesconi said.

Carli said in a statement that he has "thoroughly enjoyed" his years as the association's CEO. He suggested the association's board and managers had done a good job preparing for the transition in leadership.

"Byron Enix is a tremendous choice by the board," Carli said. "He is uniquely equipped to lead an exceptional management team into the future."