Updated from 10:52 a.m. EDT

Morgan Stanley Dean Witter

( MWD) on Thursday said it posted a 28% jump in earnings, driven by a healthy gain in trading revenue, but unlike a pair of its investment banking peers, it failed to live up to Wall Street's third-quarter expectations.

The financial services firm, based in New York, said net income rose to $1.2 billion, or $1.09 a share, in the quarter ending Aug. 31, compared with $970 million, or 83 cents a share, a year ago. The consensus among analysts, meanwhile, was $1.17 a share, according to

First Call/Thomson Financial

.

Net revenue increased 18% to $6.3 billion, up from $5.3 billion in the comparable quarter of 1999, as revenue from trading stocks and bonds climbed 43% to $1.6 billion. But strength in that area was overshadowed by its investment banking revenue, which fell 3% to $1.2 billion.

The results contrast sharply with those of

Lehman Brothers

( LEH) and

Goldman Sachs

(GS) - Get Report

, two

investment

banks that easily surpassed analysts' forecasts when they made their earnings announcements earlier this week.

In a joint statement, Philip J. Purcell, the company's chairman, and John J. Mack, its president, highlighted earnings over the last nine months, which they said are 35% ahead of last year's pace. In the first nine months of fiscal 2000, net income was $4.2 billion, compared with $3.2 billion a year ago.

Morgan Stanley Dean Witter ended Thursday regular trading down $6.38, or 7%, at $89.56.