Pay Inequality Extends to Boardroom

US companies are facing fresh pressure from regulators and shareholders to rein in excessive executive pay as research shows chief executives have been paid up to 10 times more than their top lieutenants.

The average total compensation for a S&P 500 chief executive was about twice as much as the second most highly paid executive last year, according to a study conducted for the Financial Times by the research group, Salary.com.

The gap has been rising, too, partly due to a recent explosion in options awards.

The Securities and Exchange Commission is also believed to have asked a number of companies to explain the reason for large pay gaps between top executives, as part of a review of corporate pay.