Outgoing performance chief Bill Sweetenham has hailed the ''quite outstanding'' improvement seen in British swimming during his seven-year reign.

The outspoken Australian has stepped down from his role as British Swimming's national performance director for unspecified personal reasons.

Officials have known since December that Sweetenham would not be extending his contract beyond next year's Olympics in Beijing after he sent a letter sent to chief executive David Sparkes.

In that letter he asked British Swimming if they would consider releasing him from his contract at an earlier date this year to coincide with either the conclusion of the World Championships in March or the summer meets in August.

Following a meeting, it has been decided that now would be the best time for Sweetenham to head back down under.

And he is happy that he leaves British swimming in a far better condition than he found it.

''The results we've collectively achieved have been quite outstanding,'' he said.

''Best ever results at World Championships, European Championships and Commonwealth Games are a testament to all those involved and justified spending the past seven years away from my home and my family.

''I believe that British Swimming can look forward to a great future with a tremendously talented group of athletes, coaches and staff. I wish everyone well for the future.''

Of his reasons for quitting, he added: ''My request for release from my contract was for various reasons that will remain personal to myself.''

Sweetenham oversaw a massive improvement in British performances after he took over in the wake of the Sydney Olympics in 2000, which yielded no medals and only four finalists.

He was criticised in some quarters for his confrontational, straight-talking approach and was cleared of bullying last year following an inquiry by his employers.