(Reuters) - Polish footwear and fashion retailer CCC said on Wednesday its second-quarter core profit jumped 79% year on year, mainly due to higher sales and lower costs.

Preliminary earnings before interest, taxes, depreciation and amortisation (EBITDA) came in at 401 million zlotys ($101.37 million) compared with 224 million zlotys in the year-earlier period.

Revenue rose 6% year-on-year to 2.57 billion zlotys, driven by sales growth in all business segments, CCC, HalfPrice and the Modivo Group.

Each business lowered its ratio of costs compared to sales revenue, CEO Dariusz Milek, who is also the group's founder and biggest shareholder, said in a statement.

"We would like to improve it further in the second half of the year", he added.

The group said costs in the quarter fell 1%, while retail space increased by 7%.

Gross margin rose by four percentage points to 49.5%.

($1 = 3.9557 zlotys)

(Reporting by Marta Maciag; Editing by Rod Nickel)