By Martyn Herman
LONDON (Reuters) - Harry Redknapp resigned as manager of struggling Premier League club Queens Park Rangers on Tuesday with the 67-year-old citing knee problems as his reason for stepping down.
The top flights's oldest manager, Redknapp said impending surgery meant he could no longer give the job 100 percent.
Redknapp, who has enjoyed a colourful managerial career at West Ham United, Portsmouth, Southampton and Tottenham Hotspur, took over at QPR in November 2012.
After relegation, Redknapp took QPR back up in his first full season in charge but they have struggled this season, losing all 11 away league matches - a Premier League record.
Redknapp's hopes of strengthening his squad were dashed by a quiet transfer window and whoever takes charge will have the job of steering QPR out of the relegation zone.
They are in 19th position with 19 points from 23 games.
"Sadly I need immediate surgery on my knee which is going to stop me from doing my job in the coming weeks," Redknapp said.
"It means I won't be able to be out on the training pitch every day, and if I can't give 100 per cent I feel it's better for someone else to take over the reins."
Former striker Les Ferdinand and Chris Ramsey will take temporary charge.
"I would like to take this opportunity to thank Harry for everything he has done for QPR during his time in charge," chairman Tony Fernandes said in a statement.
"We part on good terms and I would personally like to wish him all the best for the future."
Although Redknapp's coaching resume lacks a large collection of silverware -- an FA Cup triumph with Portsmouth being his only major honour -- he has been one of the country's most respected coaches and was a contender for the England manager's job while in charge at Tottenham.
Redknapp was credited for turning Gareth Bale into a marauding forward at Tottenham and taking the club into Champions League for the first time in 2010-11.
During his time at Tottenham he was cleared of tax evasion charges dating back to his time in charge of Portsmouth.