The 20-share benchmark CROBEX lost 0.48% and ended Friday's trading session at 2,796.60 points.
The narrower equity index CROBEX10, which tracks the top ten issuers in terms of free float, market capitalisation and liquidity, dropped 0.19% to close at 1,686.76 points.
Koncar's shares were the most traded stock in regular trading, generating a turnover of 161,658 euro.
Total regular turnover came in at 1.2 million euro ($1.3 million) on Friday, down from 2.3 million euro the previous trading day.
($ = 0.918 euro)