A protein complex that plays a role in DNA double-strand break repair via nonhomologous end joining. Such complexes typically contain a specialized DNA ligase (e.g. Lig4 in eukaryotes) and one or more proteins that bind to DNA ends. [ http://www.ncbi.nlm.nih.gov/pubmed/17072889 http://www.ncbi.nlm.nih.gov/pubmed/17938628 ]