Australian Group One winners Sepoy and Helmet will stand for STG15,000 ($A23,000) and STG10,000 ($A15,300) respectively in their first northern hemisphere season.

Helmet will stand at Sheikh Mohammed's Kildangan Stud in Ireland while Sepoy will be based at the sheikh's Dalham Hall in England.

Darley have announced fees for all 23 of their stallions with Dubawi heading the roster at STG75,000.

New Approach's stud fee has more than doubled for 2013 from STG22,500 to STG50,000 after a hugely successful first season for his progeny on the track.

His most famous son to date is Dawn Approach, trained like New Approach by Jim Bolger, and he went through his juvenile campaign unbeaten.

"Sepoy and Helmet, two of the world's best racehorses to retire to stud in recent years, are a very exciting addition to our European roster," Sam Bullard, Darley's director of stallions in Europe, said.

Helmet's sire Exceed And Excel will command a fee of STG35,000 at Dalham Hall, while Teofilo will stand at STG35,000 at Kildangan.