Kazunao Murata was happy in his job as deputy general manager of the corporate planning department of one of Japan's largest banks. The Sanwa Bank Limited.

Until he got a call one morning last year to report to a special ceremony the next day during which he and many of his colleagues were to receive formal transfers within the Osaka-based institution.Murata, like most of his peers, had no idea where they would be transferred by the bank.

"When my name was called, I walked to the president and received the transfer paper, but I didn't read it right away because I was sitting in front and the president was right there." When he read the paper, he discovered he had been named general manager of the bank's relatively new branch in Chicago, a city known better to Japanese for the Prohibitionera gangland slayings portrayed in syndicated American television shows than as the United States second city.

If Murata knew very little about Chicago, but he was not alone. Foreign bankers have long frequented New York City, the world's most important financial center, and Japanese bankers have had major establishments on the West Coast for many years. As recently as 1973, there were no foreign bank branches in Chicago.

But things have changed. Today there are 22 branches of foreign banks operating in Chicago. The combined assets of these foreign branches are more than $2.1 billion, which means that almost overnight foreign branches accumulated enough assets - some of them transferred from their New York sisters - to rank collectively as the fifth biggest bank in Chicago. Much of that growth has occurred at a time when bank loan demand has been depressed.

Until the 1960s - when two giant Chicago banks, Continental Illinois and First Chicago, began international operations in earnest - Chicago was an address in world commerce but not a financial force.

By the late 1960s, foreign bankers began to notice the huge industrial and agricultural business that was generated in the Chicago region, and the interest of many, especially the British giant, Barclay's Ltd., was kindled.

Foreign trade had grown sharply since World War II, and the Midwest - both the agricultural states and the manufacturing states - provided much of the nation's export commodities. Large and small companies alike had increasing need for the complicated financing that international trade requires and the help bankers can give to big and small concerns who decide to do business abroad. Simultaneously, many European and Japanese firms set up shop near Chicago to be near the burgeoning Midwest market.

But Chicago is far from New York (and even further from California). "It is hard to service a customer 700 or 800 miles away," said Jean-Louis Allez, head of the French Credit Lyonnais operations here. "The extent of our relationship with a customer is strictly dependent on the number of contacts we have."

Illinois, whose archaic, rural-dominated banking laws do not allow banks to operate under more than one roof, also had a long-standing ban on branches of foreign banks operating in the state. Pressures to loosen the ban on foreign branches became strong in the late 1960s and early 1970s - especially after Chicago-based banks opened dozens of foreign branches - and the law finally was changed effective Oct. 1, 1973.

The Illinois legislature, which has defeated attempts by the state's larger banks to introduce branching, confined foreign bank operations to downtown Chicago, an area commonly known as the Loop.

Even before the law was changed, Banco di Roma, the big Italian institution, decided to open up a subsidiary bank, a much more expensive proposition than a branch because an Illinois-chartered bank has to have retail operations and must work off its own capital base, not the base of a parent.

"But we decided that we had to go to Chicago," according to Banco di Roma, Chicago, president Mario Gabriele. "Chicago was such a tremendous industrial center that we knew one day it had to become a more important financial center. We opened our subsidiary on March 26, 1973. Six months later, the branching law was approved. The rush of foreign banks to Chicago since then confirms that our decision was correct."

In addition to the 22 foreign branches which set up shop between October 1973 and June 1975, another 10 to 15 are waiting to see whether Congress extends the prohibition against domestic banks having branches in more than one state to foreign banks as well, according to Illinois State Bank Examiner G. Lynn Cummins. The bill, which did not pass Congress last year, would have permitted foreign banks operating branches in more than one state to continue to do so, but would have prohibited them from opening any more after May 1975. No branches have opened in Chicago since then.

There are also two foreign subsidiaries - Banco di Roma, and First Pacific of Chicago, whose parent is Dai Ichi Kangyo of Japan - which operate as full-fledged domestic banks, and 20 foreign banks which maintain representative offices.

While assets of foreign branches in Chicago have risen dramatically - from nothing in 1973 to $2.1 billion in late 1976, according to figures maintained by the Federal Reserve Board - they remain small compared with New York, where foreign bank assets totatalled $41.4 billion, and California, where foreign banks have assets of $17.8 billion.

"Chicago is not the nation's biggest financial center," notes Frasier Dunnett, head of Barclay's, Ltd.'s, operations here. It is third behind New York and the West Coast.

But it already is an important one which can do nothing but grow, Dunnett said. Chicago has developed a strong foreign exchange market in the Canadian dollar.Gunther Ischebeck, a vice president of Dusseldorf-based Commerzbank, says "the market in Canadian dollars is stronger here than in New York" at times. Allez said his branch of Credit Lyonnais is specializing in trading the Canadian dollar and is performing much of the Canadian dollar transactions for the $33 billion parent.

Sanwa's Murata, like his counterparts at other foreign branches, ticks off a list of Chicago and Midwest attractions for the foreign banking community as though he were representing Chicago's Chamber of Commerce: Between 35 and 40 per cent of the total gross national product originates in the Midwest. More than 200 of the 500 largest corporations are located in the Midwest, with more than 50 of them in the Chicago area.

All of the foreign banks are basically after wholesale banking business, the accounts of large American corporations as well as those of foreign companies doing business in the Chicago area.

Some, like Commerzbank, totally eschew the retail business. Located on the 46th floor of a tall Loop building (one floor above Credit Lyonnais), the bank does not attract much traffic off the street, jokes Commerzbank vice president Rainer H. Wedel, who co-manages the branch.

"That's not why we're here. We're not equipped to do a retail business. If, for whatever reasons, a German man does not have any bank, we assist him here. But they are rare." The bank has one teller window, which is generally not manned.

His co-manager, Gunther Ischebeck, says "We should specialize in areas where we have real expertise. Mainly with American corporations who have business relations with Germany." The banks also helps its German customers establish themselves in Chicago.

"We are helping German companies start here. Most of them are small to medium-sized, privately owned companies, who had an export relationship with the United States, who thought they would be better represented with a subsidiary." He cited German firms in the medical instrument business, auto parts and office organization systems business as among those who have set up shop in the Midwest.

Murata, who has a little bigger retail operation in Sanwa's second-floor location, says his branch first seeks out the 160 Japanese trading companies and manufacturers which have Chicago subsidiaries. "Half these subsidiaries do not even have treasurers," he said.

After that, the bank deals with American companies who have business with Japan. "We can even provide a partner for a joint venture in Japan, to help cut the red tape" that accompanies doing business there.

"It is personal banking in Chicago that we cannot cater to," Murata said. Ironically, Sanwa, Japan's fifth largest bank, is the only large Japanese bank with a major retail business, Murata noted.

But many of the foreign branches, while primarily after corporate business, have jumped heavily into the competitive retail business as well, seeing personal banking as a means of exposure to big corporate customers.

Gabriele, whose Banco di Roma subsidiary must do street-level retail business under Illinois law, said the most difficult part of his job was learning how American banks go after individual accounts. "Promotion is unknown in Italy," he said. "When we first came here, we collected all the ads with promotional items to send back to Italy to show them how American banks operated. They even give away Teddy bears," he grinned.

Banco di Roma soon learned, he averred. In a publicity stunt, the bank offered a Maserati sports car as a premium for a $250,000 deposit at no interest for a year. The interest on that size deposit would have paid for the car. No one won the "free" Maserati.

"But it made the name of the bank known. It got a good deal of press interest," Gabriele said, and it also gave Banco di Roma some much-needed experience in American promotional hoopla.

"Most of my counterparts have upstairs facilities," Gabriele noted. "They envy me for being on the street level. I envy them for having a larger lending limit."

Bank Leumi, the biggest bank in Israel, has advertised its Channukah club accounts heavily, while the National Bank of Greece has made a big, apparently successful pitch to Chicago's large Greek community.

Barclays, which Dunnet says always operates as a local bank, was the first foreign branch to open in Chicago (the legislation which opened the door to foreign branches was dubbed the Barclays bill). It began promotional advertising picturing a nattily dressed Briton walking a bulldog down Chicago's main financial avenue, LaSalle Street. Barclay is the "English bank with the American accent," the advertisement claimed.

Trying to sell individual accounts is difficult. Except for the two subsidiaries which are American banks, foreign banks in the United States cannot buy federal deposit insurance. Nor, notes one branch manager, is a motel clerk in Iowa "going to be excited about accepting your check on a bank based in Europe."