World food prices rose slightly in April, up for the third month in a row but they remained almost 10 percent lower than a year earlier, the United Nations food agency said on Thursday.

The Food and Agriculture Organization's (FAO) food price index, which measures monthly changes for a basket of cereals, oilseeds, dairy products, meat and sugar, averaged 151.8 points, up 0.7 percent from March.

The index has declined annually for four straight years to near seven-year lows amid slowing global growth, but ticked up in April as gains in vegetable oils and cereals offset declines in dairy and sugar.

Food prices on international markets in April were almost 10 percent lower than in the same month a year ago and more than one third off historic highs hit in 2011, with only sugar and vegetable oils more expensive than in April 2015.

Palm oil, quoted at a 17-month high, drove the increase in the overall index as concerns about a grim production outlook for the cooking ingredient coincided with rising global demand.

Cereals contributed more gently, rising 1.5 percent on the month mainly thanks to the influence of a weaker U.S. dollar on maize prices, and spillover from soaring oilseeds prices.

Rice prices declined marginally. Wheat markets made limited gains due to expectations of large supplies in the new season.

Growing hunger for Australian beef in the United States pushed the meat price index up 0.8 percent.

The FAO said world cereals output in 2016-17 could be the second-largest global harvest ever at 2.526 billion tonnes, almost unchanged from the previous year.

World wheat output is due to hit 716.9 million tonnes in 2016-17, the FAO said, raising its previous forecast.