Aug 30 (Reuters) - Powszechna Kasa Oszczednosci Bank Polski SA
* Poland’s biggest bank PKO BP said on Wednesday it decided to buy back subordinated bonds worth 1.6 billion zlotys ($447.90 million) before maturity.
* The bank said it received the financial market regulator approval to buy back the bonds before their maturity.
* PKO said will buty back the bonds on September 14 2017. Source text for Eikon: Further company coverage: ($1 = 3.5722 zlotys) (Reporting by Agnieszka Barteczko, editing by Louise Heavens)