Manchester United have signed Dutch centre back Matthijs de Ligt and Morocco full back Noussair Mazraoui from German side Bayern Munich.

British media reported that the pair were signed for a combined fee of 60m euro ($A99m)

The pair started their youth careers at Dutch side Ajax Amsterdam and went on to play under now-United manager Erik ten Hag in the first team.

The 25-year-old De Ligt won the Eredivisie in the 2018-19 season with Ajax, the Serie A title in 2019-20 with Juventus and the Bundesliga in 2022-23 with Bayern.

"Erik ten Hag shaped the early stages of my career, so he knows how to get the best out of me and I cannot wait to work with him again," De Ligt said in a statement.

Mazraoui, 26, joined Bayern from Ajax in 2022 and went on to make 55 appearances across all competitions, winning the Bundesliga in his debut campaign. 

"Erik ten Hag played an important part in my development as a player, so it is exciting to be reuniting with him as I enter the prime years of my career," Mazraoui said.

"I know what he expects from his players, and I will give everything to help the group be successful."

Earlier on Tuesday United sold Aaron Wan-Bissaka to West Ham for a reported fee of 15m pounds ($A29m)

Elsewhere in the Premier League Cole Palmer signed a two-year contract extension with Chelsea. 

It committed the 22-year-old, who shone after joining from Manchester City last September, forcing his way into the England team, to the Blues until June 2033.

Bournemouth signed Mexico defender Julian Araujo from Barcelona on a five-year contract. 

Born in California, the 23-year-old right-back started his career at LA Galaxy before moving to the Spanish giants in 2023.