工行 is the short form of 中国工商银行 (Industrial and Commercial Bank of China). By total assets it has been the world's largest bank for over a decade. Part of the Big Four: 工、农、中、建 (ICBC, ABC, BOC, CCB).
memory
工 (industrial) + 行 (bank) — the 'I' in ICBC. Note 行 here = háng (firm/bank), not xíng.
