Ah, yes. I did restrict my remarks to UK carriers, as
Pilot16 is based in London. I am aware that Cathay and Emirates fly newly-graduated fATPLs as cruise pilots in A340/B744/B777. In fact, we in Virgin did the same a few years ago but decided in 1999 or 2000 that it wasn't economically viable to run a small section of SOs that couldn't be used on the normal roster as FOs. As £6 mentions, you also need to get the APIC qualification to be fully useful in the long-haul business, which disqualifies all fATPL holders.
I'm sure that there are other airlines that do use low-hour pilots in long haul around the world, and good luck to them. I myself was qualified P1 on the 'Mighty Hercules' with less than 400 hours under my belt, and the RAF still sends baby co-pilots off all around the world (and to war) with very low hours on the E3 (B707), Nimrod, Tristar (L1011-500), C17, VC10 and C130. These are all serious heavy metal. Not only that, but these guys may be commanders on these types with around 1500 hours or less. If it's OK for the RAF, there's no reason why it shouldn't be for anyone else!