Taking into account various investigations and administrative fines as well as competition problems such as high price increases and market sharing in the cement sector, the Turkish Competition Authority published Cement Sector Inquiry Report in order to identify sources of the competition problems and develop structural or behavioural solutions. In the Cement Sector Inquiry Report, it was found that sales price for grey cement was not directly related to economic parameters such as seasonality, demand or costs; undertakings acted in accordance with joint profit maximization bahaviour in most of the regions; and the sector was far behind the optimal competitive level. Whether the competition problems resulted from alleged infringements of competition or rational preferences of the undertakings within the framework of oligopolistic behaviour was beyond the scope of the Cement Sector Inquiry Report. The Cement Sector Inquiry Report is available via http://www.rekabet.gov.tr/tr-TR/Guncel/Rekabet-Kurumu-Cimento-Sektor-Raporu-Yayimlandi http://www.rekabet.gov.tr/tr-TR/Guncel/Rekabet-Kurumu-Cimento-Sektor-Raporu-Yayimlandi