Bank One Corp. spent $1.2 billion in the third quarter, bolstering its  badly sagging stock and accounting for more than one-fifth of total stock   buybacks by the nation's 25 largest banks.   
During the period, Bank One's shares fell more than 38% after it said  it would not meet earnings projections. The statistics, compiled by Keefe,   Bruyette & Woods Inc., do not include any activity in the fourth quarter,   when Bank One again stunned the market with bad news about its earnings,   causing its stock to sink further.       
  
Bank One and three others -- Bank of America Corp., Bank of New York  and Chase Manhattan Corp. -- accounted for more than two-thirds of bank   stocks repurchased, in terms of dollars.   
The $5.7 billion spent by the top-25 U.S. banks to buy back shares in  the third quarter was the highest in more than two years. The share   repurchases accelerated the pace of the first half of the year: Banking   companies spent $5 billion in the second quarter, and $5.1 billion in the   first.       
  
Buyback activity this year marks a return to what typically had been  the top of a normal range of repurchasing. Banks last year -- in the   aftermath of a merger wave -- were slow to repurchase stock because of a   Securities and Exchange Commission rule that bars companies from buying   back stock for six months after a merger that uses pooling-of-interests   accounting.         
Aside from Bank One, other banks that made big repurchases included:  Bank of America, $1.1 billion; Bank of New York, $850 million; Chase, $780   million; Wachovia Corp., $546 million; Mellon Financial Corp., $225   million; and Firstar Corp., $210 million.     
Bank One's board authorized management to buy back 65 million shares in  May. More than half that was used in the third quarter, but it is not clear   how much, if any, of the remaining authorization had been used in the   fourth quarter. Bank One declined to comment Friday on fourth-quarter   buyback activity.       
  
But Tom Kelly, a bank spokesman, affirmed that Bank One had repurchased  a "heavy amount" of its stock in late September. According to Keefe,   Bruyette, it was 32 million shares for the third quarter as a whole, at a   price in a range of $37 to $38 a share.     
When the buybacks were authorized in May, Bank One had planned to make  the purchases over a "few" years, Mr. Kelly said. In contrast to the 32   million shares it bought in the third quarter, it repurchased only 5   million shares late in the second quarter.     
Before the first downward revision of its earnings estimates, Bank One  stock was trading at about $55 a share. It tumbled to $43 following the   announcement, hitting a third-quarter low of $34.3125 on Sept. 27. It   dropped further in the fourth quarter, hitting a low of $32.6875 on Oct.   15. On Friday, it closed at $36.50.       
Mr. Kelly said Friday that the bank is prepared to step into the market  again. Without saying whether it repurchased any shares this quarter, Mr.   Kelly said the company is well capitalized and can afford to buy more   shares.     
  
According to a filing with the Securities and Exchange Commission, Bank  One's tier-one capital was 7.7% of assets at the end of the third quarter. 
The buybacks enabled Bank One to repurchase its shares at  bargain-basement prices, assuming they will rise in the future. Perhaps   more important, the repurchases gave support to the stock's price when it   was under severe downward pressure.     
The pressure was so great that a number of analysts, including David  Berry of Keefe, Bruyette, said the company could become a takeover target. 
"A company has to manage its share price, otherwise it becomes  vulnerable to a takeover," said John Otis, a bond analyst for Bear, Stearns   & Co.   
The buybacks also helped market psychology, analysts said.
Michael Laliberte, an owner of Bank One stock and co-adviser for the  Imperial Bank Fund, a portfolio managed by Retirement Planning Co. in   Providence, R.I., said Bank One was giving investors reason to believe top   executives have faith in the company.     
"It makes the most amount of sense from a public relations standpoint,"  Mr. Laliberte said. The buyback program "is one of the few things   sustaining the credibility of management."   
On Nov. 10, the bank confirmed market rumors of the previous day that  its fourth-quarter earnings would be lower than expected. Based on the   rumors, the stock fell more than $4, to $34.625, the day before the   announcement. The stock regained almost all it had lost in the following   trading days. Trading in the stock was unusually heavy.       
Other banks that were heavy purchasers of their own stock in the third  quarter did so largely because they could not invest available funds in   ways that would sufficiently bolster stockholder equity.   
"The best use of capital is to grow your business," said Marni Pont  O'Doherty, an analyst with Keefe, "but if none of those opportunities above   a certain hurdle rate are not there, then it's best just to return the   capital to shareholders."