WASHINGTON  - Federal Reserve Chairman Ben Bernanke told Congress today he didn't pressure Bank of America into acquiring Merrill Lynch in a deal that ultimately cost taxpayers $20 billion.

Bernanke, in prepared testimony to a House committee investigating the matter, said he did not threaten action against Bank of America's CEO Kenneth Lewis or the bank's board members if they decided to abandon the takeover.

"I did not tell Bank of America's management that the Federal Reserve would take action against the board or management" if they decided to invoke a clause in the acquisition contract in an attempt to stop the deal, Bernanke told the House Oversight and Government Reform Committee. "Moreover, I did not instruct anyone to indicate to Bank of America that the Federal Reserve would take any particular action under those circumstances."

Earlier this month, Lewis testified that his job was threatened after he expressed second thoughts about the deal. Lewis said then-Treasury Secretary Henry Paulson and federal regulators made clear that if Charlotte-N.C.-based Bank of America Corp. reneged on its promise, that he and the bank's board members would be ousted.

Bernanke said no member of the Fed ever urged Bank of America to keep quiet about Merrill Lynch's financial problems. Not divulging that information would have violated Lewis' fiduciary duty to the bank's shareholders.

"Neither I nor any member of the Federal Reserve ever directed, instructed or advised Bank of America to withhold from public disclosure any information relating to Merrill Lynch, including its losses, compensation packages or bonuses or any other related matter," the Fed chief said.

It marked Bernanke's first public comments since the House committee launched an investigation earlier this year into whether he or other government officials bullied Bank of America to stick with its plan to combine the two financial powers after Lewis found out about Merrill's financial woes.

Bank of America received $45 billion from the government's financial bailout program, $20 billion of which was linked to its acquisition of New York-based Merrill Lynch.

Bernanke defended the deal and government bailout, saying the action was needed to avoid another blow to the financial system, which at the time was in distress.

If Bank of America had decided to abandon the deal, it "might have triggered a broader systemic crisis that could well have destabilized Bank of America as well as Merrill Lynch," Bernanke said.

The government helped orchestrate the deal at a time when the country's economic and financial landscape was especially fragile. Lending, the lifeblood of the economy, had come to a near halt and the financial system was on the brink of a meltdown.

The transaction was hammered out  in September that another investment bank, Lehman Brothers, went under, leading to the biggest corporate bankruptcy in U.S. history and plunging financial markets worldwide into crisis. Bank of America completed its purchase of Merrill Lynch on Jan. 1.