Onbancorp said it would continue litigation against  a dissident shareholder despite his statement that he is backing down   because of an injury.   
On Tuesday, Seymour Holtzman, who owns 2% of Onbancorp's stock, said he  would withdraw his proposal to the board that it sell or merge the bank.   Mr. Holtzman said he had broken two ribs in a bicycle accident.   
  
Robert J. Bennett, Onbancorp's chairman and chief executive officer,  suggested Mr. Holtzman is using the injury as an excuse to avoid testifying   in the litigation over the solicitation effort.   
The Onbanc chairman suggested that Mr. Holtzman eventually will renew  his effort to force a sale or merger, and that the bank still wants to take   his sworn testimony.   
  
Charles Garcia, a spokesman for Mr. Holtzman, said he won't push his  plan at the 1997 shareholder meeting. Mr. Garcia, of the Garcia & Cope law   firm in Boca Raton, Fla., cited the "heated" litigation.