The private investors that so far declared their participation in Greece's debt restructuring hold about 20 percent of the bonds involved in a swap required for an international bailout.

The 12 members of the creditors' steering committee that said yesterday they would join in the exchange have debt with a face value of at least 40 billion euros ($53 billion), compared with the 206 billion euros of Greek bonds in private hands, according to data compiled by Bloomberg from company reports.

European officials are pressing investors to swallow the writedowns to avert even greater losses. The participating firms include some of Greece's biggest creditors, including National Bank of Greece SA, Alpha Bank SA, BNP Paribas SA and Commerzbank AG. The goal of the swap, which runs through March 8, is to reduce by 53.5 percent the total of privately held Greek debt, helping avert an uncontrolled default that could roil markets and spur contagion to states such as Portugal.