LONDON, June 14 (Reuters) - Abstract paintings depicting thefemale form by Pablo Picasso and Fernand Leger are expected tofetch tens of millions of dollars at auction when they go underthe hammer next week, according to Christie's auction house.

"Femme dans un fauteuil", painted by French cubist artistLeger in 1913, is one of a group of five figurative worksfeaturing a seated woman. It has an estimated price tag of 25million pounds ($31.56 million).

Picasso's green "Homme et femme", painted by the Spanishartist in a day in 1968, is a self-portrait of himselfintertwined with his wife Jacqueline, according to Jason Carey,head of impressionist and modern art at Christie's. It isestimated to sell for 10-15 million pounds, he said.

Also for sale at Christie's "Impressionist and Modern Art"sale on June 18 is a 1937 painting by French artist HenriMatisse, of a young female model wearing clothes he bought atmarkets in Nice. It is seen fetching 5-8 million pounds.

"We have Asian collectors, we have new buyers, we havecollectors of contemporary art who are looking back to theavant-garde as well like artists such as Leger," Carey said ofthe appetite for modern art. "There's really competing forces."

($1 = 0.7922 pounds)

(Reporting by Emily Roe and Marissa Davison; editing by JasonNeely) ((Marie-Louise.Gumuchian@thomsonreuters.com; +44 207 542 2290;Reuters Messaging:marie-louise.gumuchian.thomsonreuters.com@reuters.net))