This excerpt taken from the C 8-K filed Jan 21, 2009.
3. Grant Price Exercise Condition. A vested option may not be exercised unless and until, and then only to the extent that, the New York Stock Exchange (“NYSE”) closing price of Citigroup stock equals or exceeds the applicable grant price indicated in the Stock Option Grant Summary on page 1 for at least 20 NYSE trading days within any period of 30 consecutive NYSE trading days starting on or after the option grant date but ending no later than the option expiration date (the “Grant Price Exercise Condition”). Once the applicable Grant Price Exercise Condition has been attained, whether before or after a Vesting Date, the vested options will remain exercisable until the option expiration date, regardless of subsequent stock price performance.
Vesting is conditioned on Participant’s continuous employment with the Company up to and including the scheduled Vesting Date, unless otherwise provided below.