NEW YORK » A lawsuit filed against accounting giant Ernst & Young marks one of the biggest government efforts to date to assign blame for the financial crisis.

The suit by Andrew Cuomo, the outgoing New York state attorney general, accuses Ernst & Young of helping Lehman Bros. cover up its declining health in the months before the investment bank’s collapse in September 2008.

Cuomo’s complaint, filed in state court, focuses on a set of short-term transactions, begun in 2001, that allowed Lehman to look healthier and less risky when it reported quarterly financial data.

The suit accuses Ernst & Young of approving the "Repo 105" transactions and signing off on financial reports that did not disclose them.

Ernst & Young "sat by silently while Lehman deceived the public," the complaint says.

The New York accounting firm issued a statement saying it would fight the suit.

"Lehman’s audited financial statements clearly portrayed Lehman as a highly leveraged entity operating in a risky and volatile industry," the accounting firm said. "Lehman’s bankruptcy was not caused by any accounting issues."

The suit recalls accusations that followed the collapse of energy giant Enron in 2001, when prosecutors blamed accounting firm Arthur Andersen for many of Enron’s problems.

A criminal indictment of Andersen forced it out of business, reducing the five big U.S. accounting firms to four, including Ernst & Young.

The case filed yesterday, however, is civil, not criminal, and will probably end with a monetary settlement. The complaint asks the court to order Ernst & Young to pay New York the more than $150 million in fees that the firm collected from Lehman.

Although there have been reports of similar accounting maneuvers at other big banks, legal experts say they do not expect a wave of litigation seeking to blame the accounting industry for the financial crisis.

The financial crisis was not "driven by misconduct or poor performance by the accounting firms," said John Eickemeyer, a New York lawyer and expert on accounting law. "I really don’t think that this is going to start a trend."

The case is the latest effort by government authorities to expose behavior that contributed to the crisis; perhaps the biggest case to date was a regulatory action that the Securities and Exchange Commission brought against Goldman Sachs in April and settled in July.

So far, federal authorities have struggled to bring and sustain big cases arising from the crisis, and some of the more dramatic enforcement actions have been initiated by state authorities such as Cuomo.

"It’s interesting that again the New York attorney general is going out and addressing something that a bunch of different regulators have hemmed and hawed about," said Jill Fisch, a professor of securities law at the University of Pennsylvania.