Luka Koper shares closed 1.25% lower at 31.5 euro ($37.2) in a trading turnover of 8,850 euro.
The SBITOP index, which tracks the most liquid and capitalised stocks on the LJSE, fell 0.30% to 814.28 points on Monday. On Friday, the index closed 0.39% higher.
Trading turnover on the LJSE rose to 796,560 euro on Monday from 590,720 euro on Friday.
Drug maker Krka [LJE:KRKG] generated the largest trading turnover on Monday, of 324,830 euro.
Chemicals producer Cinkarna Celje [LJE:CICG] was the top blue-chip gainer on Monday, closing 2.66% higher at 186.90 euro.
($ = 0.8470 euro)