Denote by λKv the complete graph of order v with multiplicity
λ. Let λKv−λKw−λKu be the graph obtained from
λKv by the removal of the edges of two vertex disjoint complete
multi-subgraphs with multiplicity λ of orders w and u,
respectively. When λ is odd, it is shown that there exists a triangle
decomposition of λKv−λKw−λKu if and only if v≥w+u+max{u,w}, λ((2v)−(2u)−(2w))≡0(mod3) and λ(v−w)≡λ(v−u)≡λ(v−1)≡0(mod2). When λ is even, it is shown that for large enough
v, the elementary necessary conditions for the existence of a triangle
decomposition of λKv−λKw−λKu are also sufficient