In Belgium, margins rose to 1.9 percent in the fourth quarter from 1.4 percent in the third, falling sharply compared to the 3.9 percent last year.
In the United States, where the group operates the Food Lion and Hannaford supermarkets, margins were stable from the third quarter at 4.2 percent.
In January, the group said sales in the fourth quarter rose 11.4 percent to 5.795 billion euros ($6.47 billion), beating analysts' expectations, with a strong performance in the United States and sales declines in Belgium.
The group had faced industrial action in Belgium in the fourth quarter after announcing a plan to cut jobs and lower costs. In February, the group managed to settle the dispute by agreeing to limit job cuts to 1,800 with no forced redundancies.
For the group as a whole, operating profit, adjusted for one off items, rose 10.4 percent in the fourth quarter to 225 million euros ($248.69 million), above the 209 million expected in a Reuter’s poll of six analysts.
Delhaize did not give a precise outlook for 2015 but said it would continue refurbishing stores in the United States and carry out the cost savings plan in Belgium.
In a separate statement the group said that its former Chief Executive Pierre-Olivier Beckers would leave the board of directors when his term expired in May.
Dutch peer Ahold, which operates in similar markets, said last week that operating margins had fallen to 3.8 percent in the United States and to 4.8 percent in the Netherlands in the fourth quarter.
Kroger, the largest supermarket operator in the United States, will publish its results later on Thursday.