NEW YORK (CNN/Money) - Lehman Bros. and Goldman Sachs posted a higher fourth-quarter profit Thursday, helped by strength in the bond market, but profit fell at Morgan Stanley.

Results at all three firms, however, beat Wall Street forecasts despite the weak stock market and the slump in investment banking that has hurt brokerage houses.

The brokerage's results come amid investigations by New York State Attorney General Eliot Spitzer and the Securities and Exchange Commission into whether those firms' stock research intentionally misled investors. The probe could lead to more than $1 billion in total fines, sources have said.

For the latest quarter, Lehman reported earnings of $243 million, or 91 cents a share, up from $130 million, or 46 cents, a year earlier. Analysts polled by earnings tracker First Call had forecast profits of 88 cents a share.

Lehman's net revenue for the quarter rose 14 percent to $1.54 billion, a shade below forecasts.

The brokerage said its fixed-income capital markets business turned in a record performance for the second consecutive year as clients moved into safer bonds amid tough financial markets. However, merger and acquisition and underwriting volumes headed lower.

Lehman logged a pre-tax, net gain of $108 million in the quarter from Sept. 11 insurance claims. The firm was displaced from its headquarters in the attack on the World Trade Center in New York City. The company also recorded a $128 million pre-tax charge related to relocating its London offices.

For the year, Lehman earned net income of $1.03 billion, or $3.68 a share, compared with earnings of $1.26 billion, or $4.38 a share in 2001. Analysts expected full-year profit of $3.65 a share, according to First Call. Full-year revenue slipped to $6.2 billion from $6.7 billion a year earlier, matching Wall Street forecasts.

Meanwhile, Morgan Stanley Thursday said it earned $884 million, or 81 cents a share excluding charges, better than the 74 cents a share consensus forecast. Including a restructuring charge, the firm had net earnings of $732 million for the latest quarter, down from $870 million a year earlier.

Morgan Stanley, which owns Discover Card, said the credit card business and cost-cutting helped the firm beat estimates amid a downturn in investment activity. The firm said advisory revenues, which come from merger and acquisition activity, were down 16 percent from a year ago. Underwriting revenue was also lower, as were fixed income and equity sales.

Goldman Sachs Group Inc. reported higher earnings Thursday, helped by less borrowing and lower operating costs.

The brokerage reported net income of $505 million, or 98 cents a share compared with earnings of $497 million, or 93 cents a share a year earlier. Analysts polled by First Call expected 96 cents a share profit.

Goldman, a top stock underwriter and adviser on mergers, said its investment banking revenue fell 34 percent in the quarter on the lower activity in those areas. But lower U.S. interest rates meant it was less expensive for companies to borrow money, and Goldman's interest expense fell nearly 20 percent.

Goldman's (GS: down $0.29 to $73.41, Research, Estimates) shares initially headed higher in Thursday trading following its report, then gave ground. Morgan Stanley (MWD: up $0.53 to $41.63, Research, Estimates) and Lehman Bros. (LEH: up $0.74 to $56.70, Research, Estimates) were up Thursday in mid-morning trade.