Nestle, the world’s biggest food group, has reported rising sales but says it is having a “challenging year”.

The Swiss company said its sales in the first three months of 2012 were 21.4 billion Swiss francs ($23.4 billion), up 5.6% from the same period last year.

The group behind KitKat and Nespresso said that the trading environment had been subdued in many developed markets.

But it added that in most emerging markets “conditions remain dynamic and rich in growth opportunities”.

Nestle, the world's biggest food group has reported rising sales but says it is having a "challenging year"

Nestle struggled in 2011 with the strength of the Swiss franc, which cut its earnings by 13.4% in the full year.

But in the past six months the Swiss central bank has been intervening to weaken its currency and support the country’s exporters.

Nestle said an expected “improved raw material environment” in the second half of the year together with rising prices meant it could maintain its forecast of improved earnings and profit margins for the full year.

It did not comment on the deal it is expected to finalize this month to buy Pfizer’s infant nutrition business for about $9 billion.