WASHINGTON  Two economists with longstanding ties to the Federal Reserve warned Congress on Thursday that it would be a mistake to make the Fed a super-regulator in charge of reining in “systemic risk” and financial institutions considered “too big to fail.”

In what is shaping up as a political battle over a crucial part of President Obama’s plan to overhaul financial regulation, the economists told a House panel that the Fed had consistently failed to recognize financial catastrophes until they were well under way.

“I do not know of any single clear example in which the Federal Reserve acted in advance to head off a crisis or a series of banking or financial failures,” said Allan H. Meltzer, professor of political economy at Carnegie Mellon University and the author of a history of the Fed.

In written testimony prepared for the House Financial Services Committee, Mr. Meltzer ticked off a long list of financial crises  the Latin American debt crisis of the 1980s, the savings-and-loan collapse of the early 1990s, the collapse of the dot-com bubble and the recent binge in reckless mortgages  and argued that the Fed had either failed to take preventive action or made things worse.