British boxer of Pakistan origin Amir Khan announced on Friday that he was retiring from boxing after a 17-year professional career.

The 35-year-old fighter, who became a unified world champion at light-welterweight, hangs up his gloves with a record of 34 wins from his 40 fights.

The 2004 Olympic silver medallist won the first 18 contests of his pro career, becoming one of the finest British boxers of his era.

Khan's career ended in defeat when he was stopped in the sixth round of his grudge match against long-time rival and compatriot Kell Brook in Manchester in February.

Brook announced his own retirement last week.

“It's time to hang up my gloves. I feel blessed to have had such an amazing career that has spanned over 27 years,” Khan wrote on his Twitter account.

“I want to say a heartfelt thanks to the incredible teams I have worked with and to my family, friends and fans for the love and support they have shown me.”

Khan became world champion in 2009, defeating Ukraine's Andriy Kotelnik in a WBA super-lightweight bout and saw off US opponent Zab Judah to add the IBF belt two years later.

A controversial points loss against American Lamont Peterson later in 2011 brought Khan's reign to a frustrating end.

Khan, who also challenged for world titles at welterweight and middleweight, lost to Mexico's Saul Alvarez in 2016 and was also stopped by American Terence Crawford in 2019.