TMK, they've held the maximum allowable percentage of shares that a foreign investors are allowed ever since the ~2005 WTO, which might be as high as 40% by now (the limits have increased every year, and won't cross 50% for the foreseeable future).

As part of this arrangement, BofA was required to close its Shanghai branch only a few years after it opened.

Other US banks are playing the same game, but no others have substantial holdings in top 5 players (tmk, I'm not so current on this stuff any more).