(a) The chief administrative officer may grant an employee sick leave in addition to that provided by sections 337.7 and 337.8 of this Part. Such additional sick leave may be at full salary, or such part thereof as the chief administrative officer may determine, or without salary. Additional sick leave at full or partial salary, together with use of any sick leave provided by sections 337.7 and 337.8 of this Part, shall not exceed a total of six calendar months. Additional sick leave without salary shall not exceed one calendar year. Additional sick leave at full or partial salary pursuant to this subdivision shall not be approved until all sick leave credits accumulated pursuant to sections 337.7 and 337.8 of this Part have been exhausted.

(b) The chief administrative officer may grant an employee sick leave in addition to that provided by subdivision (a) of this section. Such additional sick leave may be at full salary, or such part thereof as the chief administrative officer may determine, or without salary. The chancellor may require submission of such leave requests by an institution for his approval when he deems it in the best interest of the university.

(c) Prior to being granted additional sick leave provided by this section, an employee may be required to furnish such medical evidence from the employee's physician as may be requested or submit to medical examination by a physician selected by the college or university at its expense.