Germany's Christian Democrats said today that an independent audit found $6 million in illegal party donations whose sources cannot be traced, raising the possibility that secret slush funds managed by former chancellor Helmut Kohl could have been much larger than he has acknowledged.

Party Chairman Wolfgang Schaeuble called the discovery of the illicit funds "a very grave problem that represents an existential crisis for our party and a danger for our nation's democracy." He declared that the Christian Democratic Union is determined to enact reforms that ensure "nothing like this will ever happen again."

Schaeuble backed away from earlier threats to take legal action against Kohl, who has acknowledged handling illegal accounts worth up to $1 million in the five years before he was voted out of office in 1998. Kohl has spurned all entreaties from the party to defuse the crisis by complying with the law and identifying the donors, saying he promised them he would keep their names secret.

Instead, Schaeuble said the party would sue its former accountant, Horst Weyrauch, a close ally of Kohl who created the system of slush funds and who has been implicated in laundering money for the Christian Democratic Union through banks in Switzerland and Liechtenstein.

The long-awaited audit, carried out by the firm Ernst & Young, was supposed to clarify the party's funding practices and point the way toward a resolution of the scandal. Instead, the findings brought the party no closer to tracing the origins of the illegal donations and appear to have deepened the mystery about the nature of the slush funds.

Matthias Wissmann, the party treasurer, said the auditors identified slightly more than $1 million in unaccounted funds between 1993 and 1998, which corresponds to the amount that Kohl has said he handled in secret funds during those years. Kohl said the money was earmarked largely for local party chiefs in eastern Germany to build up party allegiance in a region where the Christian Democrats were weak and former communists were making strong gains.

But Wissmann, following a marathon party strategy session that began Sunday night and ended early today, said that another $5 million in untraceable funds was identified for the years 1989 to 1992, a period Kohl has never mentioned in describing his secret accounts.

Since they have failed to persuade Kohl to reveal the sources of the slush funds, the Christian Democrats decided to sue Weyrauch in an effort to compel him to identify the sources. Besides setting up Kohl's accounts, Weyrauch created special accounts in Switzerland and Liechtenstein that were used for the party's branch in the state of Hesse. Roland Koch, the Hesse party leader, said at least $7 million in illicit donations was stashed in a Liechtenstein account under the name of the Wren Foundation. Weyrauch was one of only two people with access to those funds.

Kohl has refused to identify the sources of the money, declaring he had given his "word of honor" to the donors. But some party members speculate Kohl may be reluctant to name the sources because rather than coming from individual donors, the funds may have been the result of commissions or kickbacks that could be related to decisions made by his government. That could make Kohl vulnerable to indictment on bribery or corruption charges.

Eckart von Klaeden, a Christian Democratic legislator who is one of the party's top legal experts, said he found Kohl's version of events difficult to believe. "If these people were respectable citizens of our land, as Kohl says, they would have freed him from this word of honor a long time ago," he said.

A parliamentary investigation will be expanded to examine whether French President Francois Mitterrand urged France's then state-owned energy firm Elf Aquitaine to channel $15 million into secret CDU coffers to support Kohl's 1994 reelection campaign. French and German television reported that the funds could be part of $40 million in missing commissions from the sale of the Leuna oil refinery in eastern Germany to Elf Aquitaine.

Documents pertaining to the deal disappeared from the chancellor's office shortly before Kohl left office.

The government of his successor, Social Democratic leader Gerhard Schroeder, has vowed to track them down.

A Kohl spokesman called the Elf Aquitaine report "another attempt at character assassination," and French Foreign Minister Hubert Vedrine, who served as Mitterrand's chief of staff, said he had never heard about such a transfer.

But last month, the French weekly Paris Match published part of a letter in which Kohl asked Mitterrand to intervene and ensure that Elf would buy the refinery.

"I would be extremely obliged if you would use your personal influence so that Elf carries out this project, without hesitation, as envisaged by the contract," Kohl wrote.

The Leuna purchase by Elf was touted by Kohl as a crucial move to implant a French presence in eastern Germany--with control over a key dimension of the country's energy grid--so that France would feel reassured about Germany's desire to maintain a special partnership with Paris even as the government and the nation's center of gravity shifted east to Berlin.

During their 13 years in power together, Mitterrand, who died in 1996, came to regard Kohl as a partner in building European unity and believed that sustaining his leadership was an important guarantee that a reunified Germany would carry out its promise of sacrificing the German mark in favor of a single European currency, the euro.

CAPTION: Christian Democratic leaders who failed to persuade former chancellor Helmut Kohl to reveal slush fund donors' names are suing the party's former accountant.