(Adds possible postponement of accepting banking lobby head position) TOKYO, March 17 (Reuters) - Mizuho Financial Group Inc , Japan’s third largest lender by assets, said on Wednesday it would set up a third-party committee to investigate a series of system failures, which it said had hurt its credibility. Mizuho, which has a history of troubling customers with technical problems, has suffered four system glitches in the past two weeks. “It’s the fact that a lot of customers have doubts on us, and Mizuho’s credibility has severely been eroded,” Chief Executive Tatsufumi Sakai said at an urgently arranged news conference. Sakai said he would consider how to take responsibility over the issue after finding out what caused the disruptions and taking preventive measures. The investigative committee would be chaired by lawyer Shuji Iwamura and more than two members would join later, according to Mizuho. The bank also said it had cancelled a management reshuffle that would have seen Mizuho Bank CEO Koji Fujiwara replaced by Managing Director Masahiko Kato from April. Mizuho reported a large-scale system breakdown on Feb. 28, affecting 4,318 automated teller machines (ATMs) out of 5,395 nationwide, resulting in thousands of bank cards and passbooks being stuck inside the devices. The bank also suffered two minor system glitches at ATMs on March 3 and 7. The latest issue on Thursday was a hardware problem at its data centre, which delayed foreign currency-denominated remittances for corporate clients. While Sakai was supposed to take up the chair of the coutry’s banking lobby group in April, he said he would consider postponing his acceptance. “If I take the position to represent the whole banking industry, that might cause troubles for other banks,” Sakai said. Mizuho started operating its current system in July 2019 after spending more than 400 billion yen ($3.67 billion) to develop it, following large-scale system glitches in 2002 and 2011. (Reporting by Takashi Umekawa; Editing by Christopher Cushing, Edmund Blair and Kim Coghill)