Giggs's letter in full:
"Today is a fantastic day for Manchester United. Louis van Gaal is a great appointment and let me begin by telling you how delighted I am to be working with someone of his calibre. His credentials are second to none and I'm positive the club will thrive under his leadership over the coming years.
"I would also like to take this opportunity to announce my retirement from professional football and embark upon a new and exciting chapter in my life, as assistant manager of Manchester United.
|MAN UTD APPOINT VAN GAAL
ALL OF GOAL'S TOP CONTENT
|VAN GAAL NAMED MAN UTD BOSS
|MAN UTD STATEMENT IN FULL
|VAN GAAL'S SUMMER WISHLIST|
|'WE'LL MAKE HISTORY AT MAN UTD'|
|IS VAN GAAL A RISK WORTH TAKING?
|MAN UTD NOW 6/1 TO WIN TITLE
"I want to also give a huge thanks to the backroom staff and support teams we have and have had at Manchester United over the years. I would not have achieved the success I have without your continuing dedication and commitment to creating the best environment to enable the players to thrive. I would not have won 34 trophies in my career without you.
"I would also like to say a special thanks to my friends and family for all your love and support.
"For me, today is a new chapter filled with many emotions - immense pride, sadness but, most of all, excitement towards the future.
"United fans, I hope, will share and echo my belief that the club - the management and owners - are doing everything they can to return this great club to where it belongs and I hope to be there every step of the way.
"To the greatest fans in world football, thank you. I have loved every minute of playing for you and representing the biggest and best club in the world."