Greek public and private sector unions will hold a general 24-hour strike on June 29 to protest pension and labour reforms agreed as part of a multi-billion euro EU-IMF bailout package, a senior union official said.

"The protest is primarily about the pension system reform," Ilias Iliopoulos, secretary general of public sector umbrella union ADEDY, told Reuters.

Unions also disagree with plans to make it easier for large firms to lay off workers and make its labour market more flexible.

Reuters