The five-year agreement extends existing contracts for 58 G90 and G97 2MW turbines installed over the last four years.
Gamesa said it is now providing O&M for 603MW in the two east European countries.
Spanish wind group Gamesa has signed a deal with Greek operator Terna Energy to provide O&M services for 116MW of turbines in Poland and Bulgaria.
The five-year agreement extends existing contracts for 58 G90 and G97 2MW turbines installed over the last four years.
Gamesa said it is now providing O&M for 603MW in the two east European countries.