A group of investment bank underwriters and companies have agreed to a nearly $600 million settlement with investors to resolve litigation over alleged fraud in the pricing of initial public offerings in the late 1990s, according to a lawyer involved in the case.

The case is settled, and we're awaiting a decision on preliminary approval, Howard Sirota, a lawyer for the plaintiffs said on Monday.

A settlement agreement could end a series of investor lawsuits beginning in late 2000, that claimed IPO companies and their underwriters artificially inflated stock prices and hid the amount of compensation actually received by the underwriters.

The litigation has encompassed more than 300 initial public offerings of high-tech and Internet-related stocks that were marketed between 1998 and 2000, at the height of the technology boom.

The defendants in the case include some of the companies that were brought public, several officers and directors of those companies, and 55 investment banks, including Credit Suisse Group and JPMorgan Chase & Co . Earlier attempts to settle the case for more than $1 billion have unraveled, as the case has gone through several appeals over the years.

This is the best we can do, so we're doing it because at the rate things are going, there could be no recovery, Sirota said, noting the declines of key defendants and other parties in the case, like Bear Stearns, Lehman Brothers Holdings Inc and American International Group .

The parties, after quite a long period of mediation, reached a settlement, said David Ichel, a lawyer with Simpson Thacher & Bartlett representing JP Morgan in the case. Our client is pleased with the outcome.

Lawyers representing Credit Suisse and some of the corporate issuers involved in the litigation were not immediately available for comment.

The settlement agreement was filed under seal on April 2 in the U.S. District Court in Manhattan, according to court papers.

According to a copy of the agreement posted on the Wall Street Journal's website, the exact settlement was for $586 million, and the banks and issuers in the case denied wrongdoing. The terms of the settlement, explaining who would pay who, were kept confidential, according to the court papers on the website.

A partial settlement by JPMorgan in 2006 was scrapped after a federal appeals court in New York ruled that the lawsuit had too many investors as plaintiffs to proceed. An even earlier previous settlement attempt would have guaranteed at least $1 billion to investors from the insurers of the companies in the case, while litigation against the banks would have continued.

The case is In re: IPO Securities Litigation, U.S. District Court, Southern District of New York, No. 21 MC 92.

(Reporting by Emily Chasan and Phil Wahba; editing by Carol Bishopric)