Insider sales at American Express Co. and American International Group have dropped to almost nothing since September-a change in behavior that would be consistent with reports of merger talks between the two.

Until last fall, top executives and directors had been active sellers of their companies' shares. According to CDA/Investnet, Fort Lauderdale, Fla., a research firm that tracks insider stock transactions, insiders at American Express have sold an average of 317,000 shares annually since 1990, while AIG insiders have unloaded an average of 542,000.

But since September American Express insiders have sold only 17,106 shares and AIG insiders have sold none.

Insiders sometimes sell when they believe the value of their shares has peaked or when approaching retirement. Officials at American Express and AIG declined to comment.

Considering that American Express' and AIG's stocks have traded at all- time highs in recent months and that the two New York companies are rumored to have been in merger talks, the absence of insiders taking profits is intriguing, said Robert Gabele, president of CDA/Investnet.

The numbers suggest that "insiders are holding on either because they expect to see even higher share prices or because they are possibly in a quiet period, which would prohibit their trading during a period where material discussions are taking place," Mr. Gabele said.

While American Express' and AIG's insiders have held their shares, some banking executives have used the stock market's recent bull run as a chance to unload holdings.

Stephen J. Trafton, chairman and chief executive of Golden State Bancorp, parent of Glendale Federal Bank, filed Wednesday to sell 420,000 of the company shares he owns. He also filed to sell another 80,000 held in a partnership with his wife. A spokesman said the sales result from Mr. Trafton's exercising options and selling the underlying shares.

At the time Golden State filed its annual proxy statement, Mr. Trafton had options on 833,333 shares. Presumably he will be able to cash in the remaining 333,333 options before Golden State completes its pending sale to First Nationwide Holdings, parent of California Federal Bank.

A spokesman for Golden State said Mr. Trafton is "diversifying his holdings" now because most of his net worth is tied up in his thrift company.

In another insider transaction, James R. Murphy, a director at Hibernia Corp. and chairman of Hibernia National Bank of Texas, evidently has filed to sell 90% of the stock he owns in the New Orleans banking company.

According to filings with the Securities and Exchange Commission, Mr. Murphy filed to sell 100,000 shares on April 28, and filed on May 1 to sell 210,697 more. As of March 1 he owned nearly 345,000 shares in Hibernia, according to the company's proxy.

Mr. Murphy, 63, joined Hibernia last year after serving as chairman of Texarkana National Bancshares, which sold to the Louisiana bank.

A Hibernia spokesman said Mr. Murphy was selling 100,000 of his shares "to diversify his investments," but said the company was not aware of his plans to sell any additional stock. Mr. Murphy did not return phone calls.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.