WMA Merger can merge all kinds of sound files into a wma file. It supports many audio formats such as WMA, MP3, WAV, MPA, MP2, AU, AIF, SND, etc, and video formats MPEG, AVI, VCD, WMV, ASF, DAT, MPE etc. If extra codecs are installed, WMA Merger can join DIVX, OGG, AC3, MKV, OGM, MKA, SVCD etc.
