LONDON (Reuters) - Mondelez International, maker of Cadbury Creme Eggs, has tweaked the recipe of the chocolate shell of its gooey treats ahead of their main Easter selling season, sparking an angry response in Cadbury's home market of Britain.

United States group Mondelez said on Monday the Creme Egg would now use a "standard, traditional Cadbury milk chocolate" for its shell, rather than sharing the same recipe as Cadbury Dairy Milk chocolate as it has in the past.

"It's no longer Dairy Milk. It's similar, but not exactly Dairy Milk," a spokesman said.

The move prompted a furious response from some shoppers in Britain, where trade unions and some politicians were critical of the sale of the near two-centuries-old Cadbury brand to Mondelez's predecessor company, Kraft, in 2010.

"Outraged!" said a woman with the Twitter handle #louise-gaul.

"Leave our eggs alone!"

The change only affects Creme Eggs in Britain, since those sold in the US are manufactured by Hershey. The eggs are sold only in the build up to Easter in April.

Mondelez, which last year stopped selling Cadbury chocolate coins, also reduced the number of Creme Eggs sold in its multi-packs to five from six, citing "a range of economic factors".

The price of cocoa based on London futures contracts rose 13.1 per cent last year, while the New York price climbed 7.4 per cent.