PHOENIX -- Some recently modified banking regulations are causing financial institutions and credit-card businesses to come West.

Since Arizona changed its regulations a year ago, at least four major credit-card issuers have either selected the state for processing centers or are on the verge of doing so. The four centers would mean more than 4,000 jobs for the Phoenix area.

"Phoenix can now say, 'Here's the place where there's a real concentration of this type of industry,' " said Ron Azzolina, president and chief executive of the Arizona and Southwest divisions of Security Pacific Corp. of Los Angeles. "It's a favorable regulatory environment. It has a big enough population base to draw on, it has good educational facilities and it's well located."

There's a pattern developing in Arizona similar to that in Delaware, which changed some banking regulations in 1981. More than 20 financial institutions have located credit-card operations in Delaware to take advantage of the flexible law.

Arizona's new-found popularity as a home for credit-card centers results from the year-old state legislation, which gives issuers of cards flexibility in setting prices and interest rates.

Until the law changed, credit-card businesses operating in Arizona could not charge customers fees for cash advances. The new law allows such charges, and it clarifies interest rates and fees that card issuers can charge for various services.

The law, which was aimed at persuading Security Pacific to build a credit-card center here, worked. Security Pacific opened a 700-employee credit-card center outside Phoenix in January.

Security Pacific cleared the way for at least three other companies now planning credit-card centers:

Carter Hawley Hale Stores Inc. of Los Angeles, parent company of Richmond-based Thalheimers and other department stores, has committed itself to locating a 600-employee card center in Phoenix.

Dillard Department Stores Inc. of Little Rock, Ark., is working to consolidate a 1,000-employee credit-card operation in Phoenix.

Chase Manhattan Corp. of New York is soon expected to name the Phoenix area as the site for a credit-card center that would eventually employ 2,000 people.

"I think if we get Chase, all of a sudden Phoenix becomes another Delaware," Azzolina said. "Delaware changed its laws several years ago, and everybody flocked out of New York and went to Delaware to set up their credit-card operations."

Carter Hawley Hale is close to selecting a location in the Phoenix area for a processing center that it said could grow to employ 1,000 employees. The retailer is trying to decide whether to erect a building or convert an existing one in order to consolidate its five U.S. credit-card centers.

Chase Manhattan is evaluating sites in the Phoenix area for a national credit-card operations center. Chase is the second-largest credit-card issuer in the United States, with 7 million card holders.

Chase has narrowed its list to three possible sites southeast of Phoenix near Arizona State University in Tempe. The center would total nearly 400,000 square feet.

Chase's credit-card servicing now is handled in Delaware, Tampa and on Long Island, N.Y. Chase representatives have not said what will become of those operations.

In September, Dillard filed an application with the federal Office of the Comptroller of the Currency seeking permission to establish a national bank to be headquartered in Phoenix.

A national bank charter would permit the company to streamline its credit-card business, allowing it to operate under the jurisdiction of only federal regulators and not the regulators of all the states in which it does business.

While the change in Arizona's legislation has been critical in attracting the credit-card centers, some of those involved said equally important are the state's employment base, low cost of living, quality of life and economic development efforts.

"It's a very favorable climate in terms of the lifestyle and the employment work force," Lew Pollard, Carter Hawley Hale's director of real estate, said about the decision to locate the center in Phoenix.

Carter Hawley Hale representatives said other factors used in selecting the Phoenix area included the availability of suitable office space, inexpensive lease rates, advanced telecommunications capabilities and the "pro-business" attitude from economic development leaders in bringing industry to town.

Ionna T. Morfessis, chief executive of the Greater Phoenix Economic Council, said telecommunications is the economic council's top targeted industry. Companies that depend on telecommunications technology, such as the firms that provide credit-card services, are top priority for economic recruiters here.

"Because we have a critical mass of these kinds of operations now, it's far more significant," Morfessis said. "It's like the herd theory. Now that we have a critical mass, we are getting national attention."

Morfessis said American Express Travel Related Services Co. was the pioneer in the Phoenix area for companies engaged in high-technology telecommunications.

The company first opened a charge-card processing operation in Phoenix in 1969 with about 300 employees. Now it has 6,800 people there. Of that number, more than 5,400 work in customer service. The rest hold either research and development or data-processing positions.

"The single biggest factor for us being there is a superior work force in Phoenix," said American Express spokeswoman Karen Scates. "That work force provides us the ability to continue to provide quality customer service."