LOS ANGELES (MarketWatch) -- Citigroup Inc.'s C, -1.47% China branches, and possibly other banks, have stopped all cash transfers for three days and all currency conversions from yuan for nine days, Forbes reported Sunday via an article by contributor Gordon Chang. Citi reportedly made the announcement in a notice on its web portal for Chinese customers, saying the move was a result of "system maintenance of People's Bank of China," a reason Forbes's Chang described as "preposterous." MarketWatch couldn't immediately confirm the report. Chang said the move was similar to action taken in June and December of last year. "In June, for instance, the central bank used the excuse of a 'system upgrade' to allow banks to shut down their ATMs and online banking platforms. As a result, they conserved cash and thereby avoided a nationwide meltdown," Chang wrote. See the Forbes item here.