In the wake of a restructuring of the duties of HealthNet Inc.’s top management, Steven Sell was promoted Monday to president of the health insurer’s largest subsidiary, Health Net of California Inc.

Sell, who joined the company 11 years ago, has been president of MHN, the company’s behavioral health subsidiary. He earlier worked in the government and specialty services division.

Woodland Hills-based Health Net last week reported third-quarter net income that came in well below expectations in part due to higher medical costs. The health insurer also cut its full-year outlook.

In the restructuring announced last week, Chief Executive Jay Gellert, also the board’s chairman, will focus on the company’s strategy, while Chief Operating Officer James Woys will assume responsibility for all operational matters. Stephen Lynch, president of the health plan division, plans to retire at the end of February and will report to Woys until then.

Prior to joining Health Net, Sell, 42, consulted to several health care and financial services clients on behalf of Booz Allen Hamilton and he held a variety of strategic and operational roles at The Prudential. He received his bachelor’s degree in economics and political science from Swarthmore College and his master’s degree in business administration from Stanford University.