Swimwear brand Speedo has extended its partnership with top US swimmer Michael Phelps until 2013, as the company adapts to new technology guidelines in the sport designed to even out the field.

Swimming's governing FINA last month ruled that as of 1 January 2010, only "textile fabric(s)" swimsuits will be allowed, and they shall not extend above the navel nor below the knee for men.

In a statement today Speedo said it will announce an updated - and "comprehensive" - range of elite swimwear that conforms to the new FINA rules. Phelps serves as part of an athlete advisory group to the Speedo Aqualab, which researches new technologies in the sport.

"Michael has transformed the sport of swimming, with more fan interest and participation than ever before," said Joe Gromek, CEO and chairman of US licensee Warnaco.

Phelps famously showcased the the Speedo LZR Racer swimsuit at the 2008 Beijing Olympics, where he won eight gold medals. Since then a sequence of swimwear innovations have sparked the freefall of long-established world records.