This excerpt taken from the BP 20-F filed Mar 6, 2007.
Cash Options/Stock Appreciation Rights (SARs)
These are cash-settled share-based payments available to certain employees that require the group to pay the intrinsic value of the cash option/SAR to the employee at the date of exercise. There are no performance conditions; however, participants must continue in employment with BP for the first three calendar years of the plan for the options/SARs to vest. Special arrangements may apply for qualifying leavers. The options/SARs are exercisable between the third and 10th anniversaries of the grant date.
Employee Share Ownership Plans (ESOPs)
As at 31 December 2006, there were also 1,534 preference shareholders.