Turkey's leading cement group, OYAK Holding is merging five cement companies traded on the Istanbul Stock Exchange.

OYAK Group is an industrial and financial conglomerate owned by the Turkish military's pension fund. It's decision on the merger was made "to create synergies in line with our strategic plans and our targets for the cement sector," OYAK said in a statement to the Istanbul Stock Exchange late on Monday.

OYAK Group said talks between its units had begun on the merger in line with relevant laws and regulations. The five companies are: Adana Çimento, Mardin Çimento, Denizli Çimento, Bolu Çimento, Ünye Çimento and Aslan Çimento. OYAK also owns Denizli Çimento, which is not listed. The six firms have a total grinding capacity of 22.5Mta.