Commonwealth Bank is likely to receive an earnings fillip from one of its Chinese banking arms when managing director Matt Comyn unveils the group's full year profit result in August.CBA has a strategic stake in the Shanghai-listed Bank of Hangzhou, which has reported a 19.1 per cent rise in June half profit to 3 billion yuan (A$608 million).The associate interest in Bank of Hangzhou is treated in the CBA's accounts under the equity accounting method, which means the Australian bank reports the associate's earnings in the group bottom line.Based on the preliminary disclosures made by the Bank of Hangzhou to the Shanghai stock exchange, CBA's share of the June half profit is roughly $110 million.However, the modest earnings boost from the Chinese business is unlikely to quell investor anxiety about CBA's 2018 broader earnings, which look sure to be much lower than the record $9.93 billion bottom line reported for the 2017 financial year.CBA has already revealed that it lost earnings momentum over the March 2018 quarter, when cash earnings fell by nine per cent.While CBA scrip rallied solidly in the last month, investors yesterday returned to savaging the share price.The CBA stock underperformed most other major banks on ASX trading, sliding $1.67 or 2.19 per cent to $74.43.Leading analysts last night were slightly baffled by the big fall, given that senior management had already signalled a mediocre full-year profit."Some people are worried the bank will deliver a softer result ,but that's been the expectation for some time," said CLSA analyst, Brian Johnson."I can't really add any more insight than that."The way CBA accounts for the Bank of Hangzhou investment is likely to become a matter of increasing concern to analysts in the next 12 months.The backdrop of the royal commission into misconduct in financial services seems a deeper wound for Commonwealth Bank than some of its peers, a function of its integrated financial advice model and ownership of the much complained about Bankwest.The overarching piece of M&A consuming Commonwealth Bank at present is its planned demerger of wealth management and other problem divisions from its hardier core banking businesses. The reorganisation will result in the demerger of five businesses from the listed CBA entity: Colonial First State, Colonial First State Global Asset Management, Count Financial, Financial Wisdom and Aussie Home Loans.Mitigating poor returns from offshore banking holdings are demanding attention all the same, with the bank aggressively reducing its exposure to financial services businesses throughout Asia.In the case of Bank of Hangzhou, CBA is prevented by Chinese regulators from offloading its stake before October 2019.Since 2014, CBA has more than doubled the carrying value of the Chinese asset in line with the growth in its earnings.However, the market value of the bank's Shanghai-listed scrip has collapsed by more than 65 per cent in the last year and is now trading near a record low of 7.5 yuan. This means that CBA could face a significant write-down if it decides to sell its interest.In December last year CBA valued its