The banking industry needs a new regulatory and supervisory framework to cope with the changes taking place in the nation's banking system, according to Comptroller of the Currency John Heimann.

Speaking to bankers at the annual convention of the American Bankers Association here, Heimann called for a "rationalization" of the existing structure of regulations -- which involves seven agencies. He told reporters afterwards that there should be a single, unified banking regulator. The present system leads to duplication and confusion, Heimann said to the bankers.

The Federal Reserve Board, Federal Home Loan Bank Board, National Credit Union Administration, Heimann's office, the Federal Deposit Insurance Corp., the Federal Financial Institutions Examiners Council and the Depository Institutions Deregulatory Committee all have regulatory roles.

He warned the bankers that "the financial services business will not only be different in the 1980s, it will be significantly more difficult." Several factors now assure that "the world for financial institutions will soon be very, very different," he commented.

Deregulation and technological change have drastically altered the banking business. Banks now face direct competition from thrift institutions, which can offer "transactions accounts, credit cards and other forms of personal credit," and from other financial intermediaries such as money market funds, American Express and Sears Roebuck and Co., Heimann pointed out.

This "erosion of the barriers of competition," along with the volatility in the economy, contributed to the tide of change, he said.

Federal Reserve Chairman Paul Volcker also spoke to the bankers today about the need to simplify regulations in the banking industry. He refused to comment to reporters on the recent criticism of the Fed by President Carter and Treasury Secretary G. William Miller, and opened his speech by saying that now was probably one of the times when it would be wise for the Fed chairman to be "neither seen nor heard." Volcker appears to have decided to stay out of the political arena until the election is over.

However, he did tell the bankers that "I am not St. Paul, and the Arie Theatre [where he was speaking] is not the road to Damascus," indicating that he is not about to change his mind over the Fed's year-old method of money control.

Both Volcker and Heimann addressed the particular difficulties of small bankers as deregulation proceeds space, threatening their protected markets. "Smaller banks are an important and integral part of our unique American financial system," Heimann said. He and Volcker suggested that small banks should be subject to slightly different regulations than large banks to "permit smaller well-managed banks to compete profitably alongside larger institutions," in Heimann's words.

Heimann proposed relaxing some prudence standards for smaller banks. Volcker said that "treating everyone alike in principle can in practice lead to differences in burden."

Heimann also discussed the key issue of interstate banking laws saying "the competitive vitality of commercial banking depends importantly on developing solutions to the problems posed" by the laws restricting interstate banking.

He said that "for its own sake, commercial banking" must deal with this now and proposed beginning with a phase-out of the Douglas Amendment that restricts bank holding companies from buying across state lines.

The Office of the Comptroller of the Currency believes that geographical restraints on banking are "anti-competitive and impede the effectiveness and inefficiency of the banking system," Heimann said. Moreover, other institutions "not similarly restricted" will have ample opportunity to increase their share of product markets in which banks compete," he noted. Savings and loans could be permitted to establish branches across state lines, he said, and banks already are crossing geographical boundaries for many of their activities, with the exception of deposit-taking.