Three Japanese companies agreed yesterday to pay fines totaling $137 million and to plead guilty to participating in a long-running conspiracy to fix prices for a handful of popular vitamins, the Justice Department said.

The pleas are the latest in a series of enforcement actions against the world's largest vitamin makers, which Justice officials have accused of orchestrating a nine-year conspiracy to allocate markets and set prices. The scheme led to inflated prices for bulk vitamin buyers and artificially jacked up the cost of hundreds of supermarket products.

In the deal announced yesterday, Takeda Chemical Industries Ltd. will pay $72 million for fixing prices for vitamins B2 and C; Eisai Co. will pay $40 million for fixing the price of vitamin E; and Daiichi Pharmaceutical Corp. will pay $25 million for fixing the price of B5.

Officials at Eisai released a statement of regret and announced they would launch a program to ensure that the company is observing antitrust laws. Calls to Daiichi's American offices were not returned yesterday. Takeda officials did not comment.

In May the Justice Department settled charges with three European vitamin giants that allegedly participated in the same conspiracy. Swiss drugmaker Roche Holding Ltd., Rhone-Poulenc SA of France and chemical maker BASF AG of Germany agreed to pay a total of $725 million in criminal fines.

The settlements come as the six companies negotiate a resolution to a civil lawsuit filed on behalf of nearly 1,000 bulk vitamin makers. A tentative deal in that case was struck last week, according to sources familiar with the negotiations, with the companies agreeing to pay $1.1 billion in damages and legal fees.

According to Justice officials, executives of vitamin manufacturers met three times a year to carefully divide markets--right down to the half percentage point--and establish price increases for the coming year. Participants who exceeded their quotas were punished, but there was plenty of upside to compliance. Justice officials estimate that bulk vitamin prices were 20 percent to 50 percent higher as a result of the conspiracy, leading to overcharges of hundreds of millions of dollars.

"The prosecution of these three Japanese companies further demonstrates the truly international aspect of the vitamins conspiracy," said Joel I. Klein, assistant attorney general of the Justice Department's antitrust division.