Former White House spokesman Larry Speakes quit as chief spokesman for Merrill Lynch & Co. on Friday, days after he created an uproar by admitting he twice concocted quotes for President Reagan.

Speakes said in a statement that his resignation was "the best course of action for Merrill Lynch and for me personally. Merrill Lynch is a great firm and the industry leader, and I've enjoyed being part of it."The announcement reflected intense pressure on Speakes to resign as head of communications at the Wall Street investment giant because of his disclosures in a book about his tenure as White House spokesman. He said in the book that he had attributed to Reagan comments the president never made.

Merrill Lynch said in a statement: "We accept Larry Speakes' resignation with regret. Larry has made a significant contribution to our firm during his time here, and we wish him well in every regard."

However, a source familiar with Speakes' decision, who spoke on condition he not be identified, said senior Merrill Lynch management wanted him to quit because the phony-quote disclosures raised serious questions about his credibility and by extension the credibility of the company.

Merrill Lynch spokesman Fred Yager declined to elaborate on Speakes' resignation. "I think the statement speaks for itself. I'm not going to veer from the statement," he said.

William Clark, another Merrill Lynch spokesman, said Speakes was not in the company's New York offices and his whereabouts were unclear.

Sources at the firm said Speakes asked for a meeting earlier this week with Daniel P. Tully, Merrill Lynch's president and chief operating officer, to discuss the controversy. They said the credibility issue was raised by Speakes.

"We took the attitude that he, being the communicator, knew very well what this torrent of publicity was doing to him as our chief spokesman and the image of Merrill Lynch as its chief spokesman," one source said.

Speakes joined Merrill Lynch with much fanfare 14 months ago. Sources inside the firm said he earned between $200,000 and $250,000 a year, about triple his $77,400 salary at the White House.

He oversaw a staff of about 70 people with responsibility over Merrill Lynch's press relations, corporate advertising and in-house communications.