ATHENS, Greece (AP) — Greece has extended to April 20 the deadline for a last batch of international private investors who own some euro8 billion ($10.5 billion) worth of its bonds to join in a massive swap deal and accept a deep cut in the value of their holdings.

If exchanged, the swaps will complete the biggest debt writedown in history, forgiving crisis–hit Greece just over half its euro205 billion ($271.5 billion) debt held by banks, pension funds and other private investors.

The final collection of bonds are regulated under foreign law and their owners had either earlier rejected the deal or postponed a decision in the hope of a better deal.

A finance ministry statement Thursday said that on April 11 Greece will complete the exchange for another euro20.3 billion ($26.7 billion) worth of foreign law bonds

Last month, Athens swapped bonds worth euro177 billion ($232 billion) issued under Greek law.