Shrunken Citigroup illustrates a trend in big US banks

New York

CITIGROUP became the nation's first megabank some two decades ago by expanding into new businesses while pushing to knock down barriers that limited its size. A much different Citigroup was evident last week as it reported its quarterly results. Business lines like subprime lending, which used to define the company, have all but disappeared.

Over the last seven years, Citigroup has sold more than 60 busines…