Many combinatorial problems can be efficiently solved for partial k-tr
ees (graphs of treewidth bounded by k). The edge-coloring problem is o
ne of the well-known combinatorial problems for which no efficient alg
orithms were previously known, except a polynomial-time algorithm of v
ery high complexity. This paper gives a linear-time sequential algorit
hm and an optimal parallel algorithm which find an edge-coloring of a
given partial k-tree with the minimum number of colors for fixed k. (C
) 1996 Academic Press, Inc.