Roger Millward will retire as chief executive of Swimming Teachers' Association (STA) in July 2012 after 17 years in the role.

He will step down on his 70th birthday in July 2012 and will be replaced by Alan Siddons, STA's current business development director. Millward will retain a consultative role within the association.

During Millward's tenure as CEO, STA has quadrupled its membership and increased the number of people trained to swim from approximately 1,000 per year to more than 30,000 per year in the UK.

David Candler, STA president said: "STA would not be the formidable organisation it is today without Roger Millward. His fearless determination to ensure that STA has a voice in the marketplace is one of the key reasons why STA is in such a strong position commercially and financially with a high profile nationally and internationally."