obsolete lactosylceramide alpha-2,6-N-sialyltransferase activity (obsolete GO:0047287)
OBSOLETE. Catalysis of the reaction: beta-D-galactoside + CMP-N-acetyl-beta-neuraminate = an N-acetyl-alpha-neuraminyl-(2->6)-beta-D-galactosyl derivative + CMP + H+.