UPDATE 1-Northern Trust reports profit but misses estimate

* Revenue off 1 percent

* Shares down 5 pct in premarket trading

BOSTON Oct 21 (Reuters) - Northern Trust Corp (NTRS.O) swung to a profit in the third quarter as it earned more for investing clients' money and offering other services, but results fell short of analysts' expectations.

The company, which offers private banking, investment management and global custody services, said net income was $187.9 million, or 77 cents a share, compared with a loss of $148.3 million, or 66 cents per share, a year earlier.

Analysts had expected earnings of 84 cents per share.

The company's shares fell 5 percent in premarket trading to $54.50.

Chicago-based Northern Trust said trust, investment and other servicing fees rose 10 percent, but foreign exchange trading income slumped 34 percent.

Revenue fell 1 percent to $927.6 million. (Reporting by Svea Herbst-Bayliss; editing by John Wallace)