Novel vector solitons, composed by a bright soliton and a dark or an antida
rk soliton are derived for a system of two incoherently coupled nonlinear S
chrodinger equations with the third-order dispersion. It is demonstrated th
at in the small-amplitude limit these solitons are described by the complet
ely integrable Mel'nikov system. (C) 2001 Elsevier Science B.V. All rights
reserved.