Manchester United have signed Wigan Athletic winger Antonio Valencia on a four-year deal for an undisclosed fee.

The 23-year-old Ecuador international is manager Sir Alex Ferguson's first signing since Cristiano Ronaldo signed for Real Madrid in a £80m transfer.

"Antonio is a player we have admired for some time now, having spent the last two years in the Premier League with Wigan," said Ferguson.

Valencia's transfer is reported to have cost United as much as £16m.

"I am sure his pace and ability will make a significant contribution to the team," added Ferguson.

How will Antonio Valencia do at Old Trafford

United have been in contact with Wigan over a deal for Valencia over the last "two to three months", according to Latics chairman Dave Whelan.

"I have enjoyed my time at Wigan, but I am thrilled to have the chance to challenge for the biggest honours in club football here," said Valencia, who scored three goals for Wigan last season.

"Playing in front of 76,000 fans alongside players like Wayne Rooney, Rio Ferdinand and Ryan Giggs will be an amazing experience. I can't wait to get started."

Valencia has played 34 times for Ecuador, scoring four goals.

"I hope the fans at Wigan can understand that I am an ambitious guy and a chance like this might never come again for me," said Valencia, who will be 24 next month.

"I am happy that the club has benefited from the move financially because I owe them such a lot. I have had a great time here."

Valencia's transfer is a club record for Wigan, but his departure leaves new Latics manager Roberto Martinez with the task of finding a suitable replacement.