"As the company began to market the product internationally, it was decided to modify the name of the product in each country so it would sound pleasing and realistic to consumers. This led to the introduction of Oil of Ulay (UK and Ireland), Oil of Ulan (Australia) and Oil of Olaz (France, Italy, the Netherlands and Germany).
"In 1999, it was decided to unify the brand under a global name. Thus, Oil of Ulan and Ulay became Olay on a worldwide basis, except in German-speaking regions and Italy, where it remained Oil of Olaz. In the Netherlands and Belgium, it was renamed just Olaz."
Apparently the name Olaz is more pleasing to German ears than Olay...strange indeed.