Da Italiano a Inglese Legale/Brevetti Affari/Commercio (generale) auctions

The whole phrase, talking about an auction procedure, is as follows:

"Le offerte in aumento non potranno essere inferiori ad € 10.000,00; ".

What it means in the context (it is expressed badly, I know, but you'll just have to trust me on this) is that each new bid must be at least €10,000 higher than the previous one - bids rise in scatti (and this in a sense is the word I'm groping for) of multiples of €10,000. I could just write that, but I'm sure there's some technical, and definitely more elegant way of putting it that's eluding my tired brain. Any help much appreciated!