CEO salaries themselves weren't up much last year — 2.9 percent. Bonuses rose 3.3 percent. The report said nearly two-thirds of companies surveyed exceeded bonus target levels when payout time came around — 10 percent more than did so in 2013.

"Target long-term incentives, the largest component of executive pay in major companies, increased 7.1 percent at the median in 2014, up from an increase of 5.9 percent in 2013," the report said.

Read: The salary satisfaction tipping point

"Last year was another strong year for CEO compensation," said Todd Lippincott, North America leader of executive compensation at Towers Watson. "At the same time, the results show that companies continue to manage their executive pay programs carefully. Last year was a good year financially for many companies and their shareholders. The fact that CEO pay accelerated in a year when revenue growth, earnings and shareholder returns shined demonstrates that CEOs are being rewarded for performance."

 Among other findings of the proxy analysis:

• Long-term performance plans are now the most prevalent long-term incentive vehicle and account for the largest portion of the long-term incentive mix;

• In the fifth year for mandatory say-on-pay votes by shareholders, support averaged 90 percent, about where support has been in each of the first four years, according to the study;

• 51 percent of companies used severance multiples of two or less for change-in-control payments to CEOs at the time of acquisitions, and 30 percent used a multiple of three;

• 41 percent reported a change in pension value and nonqualified deferred compensation earnings in 2014, with the median at 108 percent from 2013 to 2014.

• CEOs at small-cap companies received the largest increase in total pay, compared with their counterparts at larger companies. Total pay for small-cap CEOs increased 13.7 percent from 2013 to 2014, compared to 11.6 percent for CEOs at large-cap companies and 10.6 percent for CEOs at mid-cap companies.