Contemporary art investors will be paying close attention to Ketterer Kunst's Post War/Contemporary Art auction in Munich on May 7.

Two works by Fritz Winter are especially notable as they are appearing on the market for the first time. The oil painting Roter Bogen from 1970 has an estimate of €10,000-15,000 while Winter's Blau-Rot-Vertikal work from 1967 is expected to achieve €15,000-20,000.

George Rickey provides one of the top objects with his kinetic sculpture No title (Singel line). It was executed with a high degree of scientific accuracy in 1964 and could be yours for between €10,000 and €15,000.

Fritz Winter's Blau-Rot-Vertikal could sell for €20,000

Other highlights in the auction come from Karel Appel. His oil painting Walking Cat is estimated at €18,000-24,000 but it is the acrylic work Portrait of a Farmer from 1976 that is particularly notable. In an almost relief-like style the artist allows the colours to freely take hold of the painting. The work comes with a top end estimate of €30,000.

The auction's offerings will be completed with works by renowned artists such as Elvira Bach, Keith Haring, Bernhard Heisig, David Hockney, Sam Francis, Yves Klein, Dieter Krieg, Adolf Luther, Henri Michaux, Sigmar Polke, Gerhard Richter, George Rickey, Emil Schumacher and HP Zimmer.