Indeed, as bernardo (*GAB*!) suggests, it's from lufu which, in Old English, meant love, affection, friendliness, that kind of idea, and came from the Old High Germanic luba, lubo and lub� which gave rise to the modern-day German word Lieb, meaning... well, love.
it clearly cannot come from amor which give amour and amore. there are a group of English words which do not have the common indo european root, I think dog plough and sheep may be some of them, is lurve another?