Activists take note: Some of the largest U.S. companies are making changes in their change-in-control arrangements in response to corporate governance reform pressures.

That's according to analysis of the 125 largest companies from the 2009 Fortune 500 list by compensation consulting firm Frederic W. Cook & Co.

Eighty-eight of the 125 companies (70 percent of the sample) provide special CIC severance arrangements to their named executive officers.

Such provisions have come under increasing scrutiny in recent years. As the alert notes, shareholder activists have brought proposals seeking to limit payments under CIC severance programs, and RiskMetrics Group has designated certain features of CIC arrangements as constituting "poor pay practices" that may trigger negative or withhold vote recommendations on re-election of corporate directors.

Companies were counted as having special CIC arrangements if they offered their NEOs enhanced cash severance on a CIC-related termination. Companies that only offered equity vesting acceleration on CIC or no special CIC cash severance outside of their regular severance arrangements weren't counted as part of the sample.

Of those that provide them, 50 companies (57 percent) made changes to their CIC arrangements from 2006 to 2009. According to the alert, 20 companies (23 percent) modified their excise tax gross-up treatment. Ten companies (11 percent) eliminated excise tax gross-up altogether, while 8 percent moved from a full gross-up to a modified gross-up, under which a company pays the excise tax only if the payments exceed the safe harbor by a certain amount. Otherwise, payments are cut back to the safe harbor.

Among the other findings: Fourteen companies (16 percent) modified their treatment of equity vesting acceleration on change-in-control. Nine percent moved from single-trigger vesting—where equity vesting acceleration occurs upon a CIC—to double-trigger vesting of their equity awards, which requires the executive to lose his or her job to receive equity vesting acceleration.

Twelve companies (14 percent) modified their definition of change-in-control. Eight percent raised the acquisition threshold percentage typically to 30 percent.

Eight companies (9 percent) modified their severance multiples in the CIC cash severance formula. Seven percent reduced the multiples for the CEO and other NEOs, typically from 3X to 2X.

The full text of the alert is available here.