San Mateo County Manager David Boesch announced that he will resign effective December 31.

“It has been an honor and a privilege to lead this organization during especially challenging times,” Boesch said. “I will forever treasure this experience and the many fond memories and friendships.”

The announcement followed a closed session of the Board of Supervisors. Boesch said it was clear that he and the Board had different philosophies and that in the best interests of the organization he tendered his resignation.

Carole Groom, President of the Board of Supervisors, said the Board appreciates his many contributions and the value he has brought to the organization. She said the Board will conduct a nationwide search for a new county manager.

Boesch’s last day in the office will be November 15. Between November 15 and December 31, Boesch will provide transition assistance to an interim County Manager who has not been selected.

After serving as Assistant County Manager since February 2007, Boesch was appointed County Manager in late 2008 just as the impact of one of the worst economic downturns in the nation’s history hit California counties, leaving San Mateo County with a structural budget deficit of more than $100 million.

Boesch worked with the County’s 20 departments to set funding priorities that emphasized maintaining front-line services such as children and family services and public safety programs. At the same time, the County has worked to reduce costs by streamlining services internally and with other agencies and renegotiating pay and benefit packages with labor groups while ensuring the County received a fair share of state and federal reimbursements. As a result, the County has a balanced budget for Fiscal Year 2011-12 with a declining reliance on reserves and with a reduction in spending of approximately $30 million.

“I have a real passion for working on problems that on the surface seem intractable,” he said. “What I have learned in my career in public service is that almost any problem is solvable if you bring together the people involved and demonstrate a genuine commitment to working in partnership toward a solution.”

Boesch began his career in public service as a planner in Utah. After earning a master’s degree in public administration from Harvard University’s John F. Kennedy School of Government, he became director of community development of Nashua, N.H., and then Sunnyvale, Calif. He served as Menlo Park’s city manager from 2000 to 2007 before joining San Mateo County.