Amazon boss Jeff Bezos has challenged his rivals to increase their minimum wages, in his annual letter to shareholders.

Following the news in November that Amazon had raised its own minimum wage to $15 (£11) an hour, Bezos used his letter to “challenge” his rivals.

“Today I challenge our top retail competitors (you know who you are!) to match our employee benefits and our $15 minimum wage,” Bezos said. “Do it! Better yet, go to $16 and throw the gauntlet back at us. It’s a kind of competition that will benefit everyone”.

Bezos said the etail giant has “always offered competitive wages” but decided the time was to “offer wages that went beyond competitive” because it was the right thing to do.

For the first time, Bezos used his annual letter to also disclose physical gross merchandise sales from third-parties on the Amazon platform.

Third-party merchants accounted for 58% of total sales on Amazon in 2018, up from 3% in 1997.

Bezos said “third-party sellers are kicking our first party butt – badly”, but he added that first-party sales on the Amazon platform grew to $117bn (£90bn) last year.

The Amazon boss also said as the company continues to grow “everything needs to scale, including the size of our failed experiments” and said a firm of its size “will be experimenting at the right scale if we occasionally have multibillion-dollar failures”.