The

Philadelphia Stock Exchange

has agreed to pay $2.8 million as part of a settlement agreement with plaintiffs in a consolidated class-action lawsuit. The lawsuit, filed against the nation's options exchanges and other defendants, alleged antitrust violations by the exchanges.

In addition to the exchanges, the suit also names as defendants a host of major option market makers, which some in the industry say are the big targets of the action. The suit alleged in part that the exchanges colluded to prevent multiple listings of stock options on more than one exchange. Multiple listing is now the rule in the options market.

The plaintiffs alleged they were harmed by the purported collusion because they paid excessive transaction costs to trade options. These costs, they said, resulted from a lack of competition among exchanges for listing options.

The Philadelphia exchange denied any wrongdoing. "Although the PHLX denies the allegations set forth in the consolidated complaint in the lawsuits, the board and I felt that it was important to the PHLX's ability to move forward with its strategic initiatives without ongoing expenses and the commitment that defending this major lawsuit would have entailed," said PHLX chairman and CEO Meyer "Sandy" Frucher in a statement.

Still hanging over the industry is a major antitrust investigation that has been ongoing for more than a year by the

Justice Department

and the

Securities and Exchange Commission

.

Referring to the Justice Department and SEC probe, Frucher, in an interview Thursday, said: "As far as the Philadelphia Stock Exchange, I believe that this entire matter will be brought to closure sooner rather than later."

Last week, the

Pacific Exchange

agreed to settle the class-action suit for $4.5 million, says Dale Carlson, vice president of corporate affairs at the exchange, adding that $1 million had already been paid with the balance to be paid out over the next year or two. "We're hoping to have it wrapped up in a year," he says.

Carlson said the settlement negotiations between the Justice Department and the SEC and the Pacific Exchange are continuing.

The exchanges named along with the Philadelphia exchange and the Pacific Exchange are the

Chicago Board Options Exchange

, the

American Stock Exchange

and the

New York Stock Exchange

. The NYSE no longer trades options, but it used to.

"We're contesting the allegations in the civil suit," says a CBOE spokeswoman. "We plan to soon present a motion to dismiss. The CBOE denies the allegations in the suit," she says. The American Stock Exchange declined to comment.