FTSE-100 paper maker Mondi was able to offset lower prices in the first half with a 3% rise in underlying operating profit.The international packaging group generated underlying operating profit of €377m, up from last year's €366m. Cost management and contributions from capital investments, along with benefits from "downstream integration in key packaging segments", helped it to offset the impact of lower prices, it said.Diluted headline earnings per share for the six months to the end of June were 48.2 cents compared to last year's 45.6 euro cents.Revenues fell to $3.15bn from $3.34bn but were flat on a like-for-like basis, which excludes currency movements and disposal effects.Mondi said that sales volumes across most key paper grades were more or less unchanged from last year, "reflecting the continued slow economic recovery in Europe".Looking ahead, the company said that anticipated price increases in some packaging paper grades should provide "positive momentum" in the near term."As in prior years, the second half of the year will be impacted by the planned annual mill maintenance shuts."The interim dividend was helped by 39% to 13.23 cents per share.As of 08:42 the share price had risen 0.10% to 1,017p.WS