If they can prove they never met otherwise agreed on a price, but they just happened to take the same decision, then yes, it's not price fixing. But if they ar

If they can prove they never met otherwise agreed on a price, but they just happened to take the same decision, then yes, it's not price fixing. But if they are using the same third party that is telling explicitly telling them "your price should be this", then it's quite clear that they have agreed on the same price. Doing so indirectly doesn't make it any better.