Citicorp will deemphasize traditional local-business banking relationships to concentrate on doing business with companies that require international services, chairman John S. Reed said this week. Speaking to analysts, Mr. Reed gave few details of the corporate strategy shift but said it will take 12 to 18 months to complete. The reorientation will leave $250 billion-asset Citicorp doing "less purely local and less domestic" corporate banking business, Mr. Reed said. And he predicted that the tighter focus on serving a select group of some 1,000 companies worldwide will lead to "a smaller asset sheet, smaller risks, and better growth." The chief executive described the reorganization as part of broader change in corporate philosophy at a bank that has been run in recent years as a group of semi-autonomous entities that were free to expand as opportunities arose. "We tended to run the company to take up space," Mr. Reed said.