Abstract :
We construct three groups Λ1,Λ2,Λ3, which can all be decomposed as amalgamated products F9*F81F9 and have very few normal subgroups of finite or infinite index. Concretely, Λ1 is a simple group, Λ2 is not simple but has no non-trivial normal subgroup of infinite index, and Λ3 is not simple but has no proper subgroup of finite index.