British company bosses won pay hikes of ten percent last year, creating a growing wages gap as workers faced restraint, a study showed Monday.

The average pay package of a FTSE 100 chief executive rose to £5.48 million ($7.12 million, 6.46 million euros) in 2015, from £4.96 million in 2014, according to research from the High Pay Centre.

The think-tank, which analysed the annual reports of Britain's top 100 companies, added that chief executives were paid 140 times more than their employees on average.

“There is apparently no end yet in sight to the rise and rise of FTSE 100 CEO pay packages," said Stefan Stern, director of the High Pay Centre.

"In spite of the occasional flurry from more active shareholders, boards continue to award ever larger amounts of pay to their most senior executives."

The think-tank added that the top ten highest paid FTSE 100 chief executives were all men.

The best paid boss in 2015 was Martin Sorrell, head of advertising giant WPP, whose package soared 64 percent to more than £70 million last year.