Some 800 jobs, out of a total of 3,000, are under threat at French mushroom production and processing group France Champignon.

The group, which has cultivated the renowned "Champignons de Paris" in caves, near Saumur, in western France, since the 1930s, is turning to more efficient and profitable production techniques amid fierce competition from producers in Holland, Spain and China.

Over the next five to six years, it plans to invest just over €60m (US$57.7m) in new techniques, the downside being around 300 job cuts.

In addition, French canned vegetables group Bonduelle, is poised to take a 20% stake in France Champignon which could lead to 500 jobs cuts spread over a period of several years and the closure of two of its canning plants.

Last week, 300 staff marched through the streets of Saumur in protest to the proposed deal with Bonduelle.

By Stuart Todd, correspondent