Greece's private investors have hours to decide whether to accept a massive writedown of the country's debts.
If too few investors agree and the swap fails, the crisis-hit country is likely to default on its debt in less than two weeks.
Athens is asking creditors to swap their Greek bonds for new ones, in an exchange intended to slice about €107bn off Greece's privately held debt.
By early today, banks, pension funds and other investors holding more than half the €206bn total had publicly pledged to take part.
New legislation will allow Greece to force holdouts into accepting the deal if overall participation is not high enough.
Investors have until 8pm Irish time to state their intentions on the exchange.