December 10/Wellington, New Zealand/Reuters -- Food co-operative Land O'Lakes Inc will become the second U.S. firm to join GlobalDairy Trade, a worldwide dairy trading platform, adding a potentially big exporter of skim milk powder to the internationally traded dairy market.

Interest by firms in joining GlobalDairy Trade, which was set up in 2008 by New Zealand's Fonterra, the world's biggest dairy exporter, has picked up over the last year as demand for milk products soar in emerging economies like China.

Land O'Lakes will begin offering skim milk powder, often used in food manufacturing, via the platform in March, while it will supply butter later in 2014, GlobalDairy Trade said.

"This further demonstrates GDT's expanding role as a key platform for international trade in a broad range of dairy commodities," GlobalDairy Trade director Paul Grave said in a statement.

Known for its eponymous dairy brand in the U.S. and globally for its Purina animal nutrition brand, Land O'Lakes is the third company this year to announce it will join the platform, following India's Amul and France's Euroserum.

Fonterra supplies the bulk of product on the fortnightly auctions, which includes mainly whole and skim milk powder in addition to cheese, butter and other dairy products and sets the global benchmark for dairy prices.

DairyAmerica, Australia's Murray Goulburn and the Swedish/Danish firm Arla also supply to the platform.

Arla said last week in addition to other products, it will begin supplying skim milk powder sourced from the UK, saying it wanted to access the Asian market where prices were around 5% higher than Europe.