Fonterra is the biggest milk processor in the world, according to a report by the International Farm Comparison Network.
The network's research activities included global benchmarking of dairy-farming systems, monitoring prices and analysing developments in the sector.
Fonterra was ranked the top milk processor for 2011 with an intake of
20.5 million tonnes - equivalent to a 3 per cent market share of world milk production.
The farmer co-operative increased its share from 2.7 per cent in 2009 - when it also ranked No 1 - and led Dairy Farmers of America and Nestle, which had 2.5 per cent and 2.2 per cent respectively.
Good milk prices could lead to global growth of up to 20 million tonnes a year in 2011 and 2012, the network said.
The ANZ Commodity Price Index for dairy products fell in April and May but was still at its highest level since July 2008. The network said that between 2005 and 2010 world milk production grew on average by 11.7 million tonnes a year.
The top 21 dairy companies processed 24 per cent of world milk production.
Agricultural market analyst NZX Agrifax said New Zealand milk output in April was 31 per cent ahead of last year on a milksolids basis.
The increased output reflected excellent conditions for pasture growth during the autumn.
