News broke yesterday that Apple CEO Tim Cook was in China visiting Chinese telecom operators. China Mobile spokesperson later confirmed Cook’s visit yesterday morning. Sina Tech reports today that Cook also visited China Telecom yesterday. It is expected he’d visit China Unicom today or later as it’s the first carrier partner of Apple’s in China (report in Chinese)

It’s the second time Cook visited China this year. It is speculated that this visit is partly due to the comparatively poor performance of Apple product sales in Greater China. Apple’s latest earnings release shows that its revenues in Greater China in last fiscal quarter declined by 14% QoQ and 43% YoY. Tim Cook later explained during the conference call that decrease in sell-through was only 4% YoY and that in mainland China, actually, was up 5%.  The company also saw double digit unit growth in China for iPad.

China Mobile hasn’t officially introduced iPhone due to TD-SCDMA, the 3G format developed by several Chinese organizations and adopted by China Mobile that average chips don’t support. But it is reported that China Mobile always wanted to introduce iPhone. Early this year Tim Cook visited the biggest Chinese telecom operator for the first time. The upcoming low-cost iPhone with Qualcomm Snapdragon chip built-in reportedly will support TD-SCDMA.

Update: Cook reportedly visited China Unicom on August 1st (in Chinese).