Citigroup Inc. is considering the sale of its retail-banking business in Japan, where the U.S. financial giant has had a presence for decades as a leading Western bank, people familiar with the matter said Tuesday.

The New York company is considering a possible auction to sell the retail business, they said. The move would leave Citigroup to focus on its remaining businesses in Japan: corporate banking, investment banking and trading. Japanese loan growth has remained weak recently, amid interest rates close to zero.

Citigroup, one of the world's most sprawling global banks, has been scaling back since the financial crisis, trying to become simpler and easier to handle. The bank suffered a setback earlier this year when the U.S. Federal Reserve balked at Citigroup's dividend and share-buyback plans, citing the difficulty the firm was having measuring how a stressful scenario would affect all of its global operations.

The bank has also said it wants to home in on areas that have "the highest growth potential" for consumer banking, eschewing some smaller cities and slower-growth countries.

Since Michael Corbat became chief executive of the bank in late 2012, Citigroup has jettisoned its retail operations in countries including Honduras, Turkey, Romania, Uruguay and Paraguay. This summer it agreed to sell its consumer-banking businesses in Greece and Spain.

Citibank Japan Ltd. currently has 33 branches for the retail operations across the country and has deposits of 3.9 trillion yen ($39 billion). In the past decade, Citigroup had already shrunk its operations through divestitures of units following regulatory punishments and a series of restructurings in Japan.