By STEPHEN LABATON

WASHINGTON — Mary L. Schapiro, who appears this week at a confirmation hearing on her selection to head the Securities and Exchange Commission, has been accused in two lawsuits of making misleading statements to quickly complete a merger of regulatory organizations after which she received a 57 percent raise in her pay.

The merger involved the regulatory units of the New York Stock Exchange and the NASD two years ago. Ms. Schapiro was then head of the NASD, and she spent months traveling the country to persuade its 5,100 members to support it. The merger created a new self-regulatory organization, the Financial Industry Regulatory Authority, or Finra, where Ms. Schapiro is the chief executive. The Securities and Exchange Commission relies on Finra to police Wall Street.

Among the misstatements that she is accused of making is that the Internal Revenue Service had prohibited the NASD from paying each member more than $35,000 as part of the merger deal. Although an NASD proxy statement issued while the deal was pending said that the I.R.S. would not permit the organization to give more compensation to members, the I.R.S. did not actually issue a ruling on the matter until March 2007, long after the deal closed and three months after the members voted to approve it.

Lawyers representing Ms. Schapiro, Finra and other senior executives have fought vigorously to keep the I.R.S. ruling — and court references to details of that ruling — under seal. Last January, a federal judge in New York denied a request by The New York Times to unseal the ruling and other documents in the case.

Ms. Schapiro’s lawyer has denied the lawsuits’ allegations and, in a recent interview said that the second suit, filed shortly after her selection, is an opportunistic effort to pressure the defendants to settle. The first, dismissed by a federal district judge in New York, is on appeal.

At the S.E.C., Ms. Schapiro would be leading a government regulator that has been battered by setbacks, including its failure to uncover the apparent long-running fraud at Bernard L. Madoff Investment Securities. A recent report by the S.E.C.’s inspector general said the agency had failed to adequately police the markets and regulate Wall Street’s largest investment banks. Congressional critics have said the S.E.C.’s shortcomings contributed to the financial crisis.

The strongest proponents of the merger that created Finra were the more than 200 firms that were members of both the NASD and the New York Stock Exchange. The merger significantly lowered their regulatory expenses, but many of the smaller members were concerned about what benefits they might receive from it.

In an effort to get enough votes from the smaller firms, NASD offered each member $35,000, for a total of about $178 million, and a smaller commitment to reduce future assessments.

Executives said that amount was derived from a calculation of efficiencies from merging the organizations. NASD listed its total outstanding equity in an annual report of more than $1.6 billion. NASD officials, including Ms. Schapiro, said then that the organization could not make a greater payment because the I.R.S. had opposed it because the NASD is nonprofit.

The lawsuits challenge that assertion, saying that evidence that remains sealed undermines the NASD’s description of the I.R.S. ruling. Also sealed is an independent fairness opinion on the merger by the investment bank Houlihan Lokey Howard and Zukin Financial Advisors.

“Our cases raise questions about the transparency, truthfulness and candor of the NASD and its leadership in a major financial transaction with its own members,” said Jonathan W. Cuneo, the lead lawyer in both cases for the member firms. “It’s certainly ironic that the case involves the NASD, which is charged with policing those values in others.”

Defense lawyers said in court papers and an interview that no material misrepresentations were made. They assert that the top executives of the organization, as regulators, are entitled to absolute immunity from lawsuits. They say that the members of the NASD were not entitled to greater compensation because they do not have the same rights as shareholders of a corporation.