Despite a powerful earthquake, a deadly tsunami and growing alarm about nuclear fallout, it has mainly been business as usual in Japan for Citigroup Inc., which has the largest foreign-bank branch network in the country.

"This is clearly a fast-moving situation, but currently our Japan businesses are fully operational," Citi spokeswoman Shannon Bell said. "We have contingency plans in place, and if the situation changes this may involve moving some staff to other locations as needed to ensure business continuity."

For now, she said, Citi branches "remain open to serve our customers." The company has no branches in Sendai, one of the areas hardest hit by the tsunami.

Since 1902, when Citibank opened a branch in Yokohama, Japan has been a key international market for Citi.

The company has about three dozen branches there, including prototypes that have served as its blueprints for modernizing branches around the globe. It also has 920,000 ATMs in the country. And although it sold its Nikko Cordial securities business in 2009, Citi still has a substantial corporate banking presence in Japan, offering currency trading, syndicated lending, export agency finance and other services.

In a memo sent to Citi's work force on Tuesday, Chief Executive Vikram Pandit said the company's Asia-Pacific business had established a disaster-relief fund benefiting the Japanese Red Cross Society, with an initial contribution of 100 million yen ($1.2 million). The Citi Foundation pledged an additional $1.2 million to disaster relief, and Citi customers are now able to redeem their Citi ThankYou loyalty program points for donations starting at $25.

Additionally, Citi Cards customer service representatives have been authorized to assist affected customers with emergency cash or credit-line increase requests, and Citi's U.S. consumer and commercial banking businesses are waiving fees on wire transfers and early withdrawals from certificates of deposit, for customers sending financial support to Japan through April 5.

According to press reports Thursday, Jamie Dimon, the head of Citi rival JPMorgan Chase & Co., hopes to travel to Tokyo next week to reassure employees and clients that the company would maintain its presence there.

JPMorgan Chase has committed $5 million to relief and recovery efforts, and, like Citi, it is allowing customers to make contributions through its card and banking loyalty programs.

Bank of America Corp. also has committed $1.2 million to relief efforts.