The demise of some executive perks continues amid the ever-sharper focus on executive compensation.

The latest research from executive compensation research firm Equilar Inc. cites a decline in two key perquisites for Fortune 100 chief executives: the personal use of corporate aircraft and financial planning assistance.

While Equilar notes that both perks are “highly prevalent among America’s top corporate chiefs,” the firm reports that the prevalence and median values for both fell in the last year, and says other companies have indicated that they’ll eliminate those items from compensation programs in the near future.

From 2006 to 2007, the median value of perks related to the personal use of corporate aircraft by F100 CEOs dropped 9.8 percent, from $121,676 to $109,743. The prevalence of F100 companies disclosing the personal use of corporate aircraft by their CEO declined from 78.5 percent to 74.7 percent over the same period.

Meanwhile for the same period, the median value of financial planning benefits for those CEOs declined 9.2 percent, from $17,156 to $15,575, and the prevalence of companies disclosing that their CEO received financial planning benefits fell from 74.2 percent to 62.1 percent.

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