Apple's Japanese iTunes service boasts a million songs, but Sony's Japanese catalogue isn't on the list.
The Japan Times confirms that: "Japanese music on Sony labels is not available on iTunes".
Sony Music Entertainment spokeswoman Kiyono Yoshinaga said: "We are in talks with Apple, but we have not reached an agreement at this time."
Apple forces Japanese price cuts
Apple has entered the Japanese market with most songs costing just 150 Yen, though 10 per cent of its available content costs 200 Yen.
In Japan, operators have been charging 200 Yen.
Responding to Apple's Japanese debut, existing digital music services there announced price cuts. Sony's Label Gate, Yahoo Japan and Excite all announced such cuts, the report claims.
But labels prepare to force Apple price hikes
Digital Music News adds that Warner and JVC have also so far denied to license music to Apple's service, raising insurmountable licensing demands, such as requesting support within iTunes for competing file formats, such as Windows Media or Atrac.
It adds that labels worldwide will be renegotiating licenses with Apple in 2006, citing a report in Japan's Nikkei, which claimed labels to be, "abuzz with talk about Apple's 2006 problem".
Apple is expected to face pressure to increase prices as a result.