Average earnings of top company executives have increased by 27% in the past year because of a rise in share-based incentive schemes, according to new research.
Increases in the basic pay and bonuses of directors in FTSE-100 firms has slowed, almost to a halt, said Incomes Data Services (IDS).
But there has been a big rise in the value of long term incentive plans (LTIPs), pushing average increases in total earnings up by 27%.
The value of LTIPs rose by 81% to £938,000 for directors and to a median figure of £1.6 million for chief executives, said the report.
IDS said average total earnings of chief executives in FTSE-100 companies was £4 million in the year to June. Directors' pay increased by a median of 3.5%, while the value of bonuses fell by 4.9%, the study found.
Steve Tatton of IDS said: "Whether a reaction to Government pressure, shareholder concerns or a worse than expected business environment, it seems the brakes have been applied to the basic pay growth for FTSE-100 bosses.
"However, while shareholders will be pleased to see more traditional elements of pay seemingly slowing, these figures show that directors' earnings can still grow significantly as a result of a complex mix of incentives."
Unite general secretary Len McCluskey said: "While millions of working people are either without work, or having their pay frozen or slashed, Britain's boardrooms are finding even more devious ways to squeeze more cash from their companies. Wages for many working people have stagnated since 2003 and have fallen in real terms since the recession hit."
Unison general secretary Dave Prentis said: "The Government is guilty of allowing the gap between the rich at the top and those at the bottom to grow. It has used the recession to hold down wages in the public sector and cut jobs and services, while those at the top continue to enjoy a champagne lifestyle.
"It is clearly ridiculous that taxpayers are landed with a bill of between £6 billion and £7 billion a year for in-work benefits because scrooge bosses are lining their own pockets."