Australia captain Michael Clarke has confirmed he will retire from international cricket at the end of the ongoing Ashes series.

"I'll have one more Test and that will be the end of my career," Clarke told Channel Nine after the loss.

"I'm retiring from international cricket. I certainly don't want to jump ship and leave the boys now, so I'll play the last Test at The Oval, give it one last crack, but the time is right now."

"You never want to walk away from the game but I think my performances in this series and the last 12 months have not been acceptable to me. I pride myself on leading from the front, so that's been disappointing. You build yourself up for the big series, the big tournaments. One-day cricket is about the World Cup and Test cricket is about the Ashes.”

"I certainly tried my best, the boys tried their best and we got outplayed. We got beaten. Now it's time for the next generation of players, the next captain to have his opportunity to try and build the team and get them ready for the next Ashes series."

Clarke's change of heart following the team's dismal showing in the pivotal fourth Test means Steven Smith will lead the side to Bangladesh.

He said he made the decision to retire on Friday night after the second day's play at Trent Bridge.

"I've been lucky enough to play over 100 Test matches for Australia," Clarke said. "I've always said the game owes me nothing, I owe it everything. I'm thankful I've been able to play it for so long."

Clarke had been adamant he would keep playing for some time before this match, but another dreadful match for himself and his team has left no room for the sort of graceful home-ground exit bestowed on others.

After a three-year apprenticeship as vice-captain, Clarke replaced Ricky Ponting as captain in April 2011, and made his first Test tour as full-time leader to Sri Lanka that August.

That series was won 1-0, but it was the team's results away from home that remained a weak point throughout his tenure - winning only four of nine overseas series and suffering crushing defeats against, India, Pakistan and England.

There was also the disgrace of the "Homeworkgate" debacle in India in 2013, which led ultimately to the sacking of Mickey Arthur as coach, replaced by Darren Lehmann in June of that year.

At home Clarke's teams only lost once, to South Africa in 2012, and accomplished a 5-0 sweep of England in 2013-14.

Clarke's own batting was a key plank of his successes, but his battles with physical fitness and differences of opinion with selectors punctuated his rein and ultimately helped to wear down his run-making.

After making 12 hundreds in his first 30 matches as leader, Clarke managed only two in his last 13, and has not passed 50 in six Tests on this dual tour of the West Indies and England.

Smith has meanwhile emerged as the team's outstanding batsman, and led the Test side in three matches against India last summer when Clarke was injured.

Clarke's chronic back and hamstring problems had placed him on a collision course with the selectors at the start of last summer, when he openly defied their preference for him to play a warm-up match in Adelaide to prove his fitness to face India.

The issue was set to come to a head on November 25, the day his close friend Phillip Hughes was struck in a Sheffield Shield match at the SCG.

Clarke rushed to be by Hughes' side in hospital, and he was widely lauded for his role in helping the team and the nation as all grieved the young batsman's death.

After the first Test of the summer was shifted from Brisbane to Adelaide to allow the team extra time to come to terms with the loss, Clarke shrugged off a recurrence of his back trouble to make a courageous hundred as part of an Australian win. Clarke called it the most important innings of his career; it was his last Test hundred.