SAN JOSE, Calif. — Silicon Valley's storied financier, Frank Quattrone, won a deal from prosecutors in a New York courtroom yesterday that means an end to his legal troubles, clearing the way for him to return to the investment banking career that had made him one of Wall Street's most powerful technology bankers.

The deal represents vindication for a man who once faced an 18-month prison term for his conviction, later set aside, for obstruction of justice, as well as a "lifetime ban" from working in the securities industry.

For days, since the deal was reported imminent, Quattrone's legal victory has had valley insiders asking: Could the former top investment banker make a triumphant comeback?

"I plan to resume my business career," Quattrone said in a statement issued after the agreement was finalized in the federal courthouse in lower Manhattan. He added he was "very pleased that the case will be concluded" and looked forward to the dismissal of the charges.

Some of Silicon Valley's business leaders said they were ready for his return.

"I would hope that he would," said Dick Kramlich, general partner of New Enterprise Associates in Menlo Park, a leading venture capital firm. Kramlich, who said New Enterprise did about 20 deals with Quattrone, said he saw no reason to think Quattrone's legal odyssey would leave a stigma.

"I think he can do whatever he wants to do," said Bill Burnham, a venture capitalist who worked under Quattrone at Credit Suisse First Boston and considers him a friend. "Out here in Silicon Valley, I don't think there's anybody who is not going to welcome him with open arms, and there's a tremendous amount of sympathy."

The deal reached Tuesday was a "deferred prosecution agreement" that allows his criminal case to be dismissed without a third trial. Quattrone is required only to refrain from violating any laws and from associating with any lawbreakers for a 12-month period.

The pact would conclude a three-year effort to prosecute a man who earned $100 million in one peak year at the height of the technology industry boom as he commanded his former investment firm's technology portfolio.