Arla Foods has reported a 3.6% fall in half-year earnings off the back of poorer than expected global commodity markets and a glut in milk production.

The owner of Lurpak, Anchor and Cravendale reported that earnings per kg of milk fell from 29p last year to 28p in the first half of 2012. Arla claimed the per kg milk price – paid to its farmer owners – was the co-operative’s key financial measurement.

The fall in earnings came as revenues grew 12%, to £3.2bn as a result of organic growth and acquisitions.

Arla said it expected higher earnings in the second half of the year as prices on the global commodity markets improved. But it warned that reaching last year’s levels would be difficult.

“Market conditions in the second half of the year are still expected to be tough and while we expect to achieve higher earnings than in the first six months of the year, they will be slightly below the level of our earnings in 2011,” said chief financial officer Frederik Lotz.

Arla expected to deliver full-year revenues of £6.4bn excluding the effect of pending mergers, up from £5.8bn last year. Factoring in mergers – including that with Milk Link in the UK, which is awaiting regulatory sign off – Arla expected revenues to reach £6.6bn.

Global sales of Lurpak grew 13% in the first half of 2012, meanwhile.