awk 'FNR == 1 {
  system("[ -f \""fnt"\" ]&&mv "fnt" "fn)
  fn = FILENAME
  fnt = FILENAME"__"++c
}
ORS = /;$/ ? RS : FS {
  sub(/;$/,"")
  print > fnt
} END {
  system("[ -f \""fnt"\" ]&&mv "fnt" "fn)
}' filenames*