After a five-week trial, Judge Smith threw out the criminal charges against G.E. He concluded at the end of the government's case that prosecutors did not have enough evidence to prove a price-fixing scheme.  The prosecution's star witness was a former G.E. executive who was dismissed by the company for what it said was poor performance. Other government witnesses from G.E. provided some helpful evidence for prosecutors but also damaged their case by maintaining that they did not think there was a conspiracy. Judge Smith said that the government had failed to prove that Mr. Lotier had been working on behalf of De Beers when he received price information from G.E. and provided G.E. with information on De Beers's prices.  The apparent weakness of the government's case discouraged De Beers from seeking a settlement even though the failure to resolve the case has hampered the company's ability to do business in the United States.  Antitrust law permits the imposition of a maximum fine of $10 million, or twice the gain or loss caused by a price-fixing scheme. The indictment does not specify how much the scheme cost purchasers of industrial diamonds.  Steven C. Sunshine, one of the company's antitrust lawyers in the United States, did not return a call seeking comment. Nicola Wilson, a spokeswoman for De Beers in Johannesburg, where the company is based, declined to comment until after the conclusion of the court proceeding on Tuesday.  Luke Macaulay, an official in the public affairs office at the Justice Department, confirmed that there would be a hearing on Tuesday morning in the De Beers case but declined to comment further.  The agreement is not expected to lead to any significant related civil litigation, lawyers said. Jared Stamell, a lawyer who represented a class of industrial diamond purchasers in a lawsuit against De Beers, said the company settled that case a few years ago for $26 million. Mr. Stamell is now involved in a different civil antitrust lawsuit against De Beers involving the sale of rough diamonds.  The settlement of the criminal case will go a long way toward advancing the company's plan to expand into new markets, although a diamond industry executive said that the company had no immediate plans to change its level of business in the United States.  Three years ago, it signed a joint venture with LVMH Moët Hennessy Louis Vuitton, the French luxury retailer, to open retail operations and market luxury diamonds around the world. As the company has steadily lost market share in the world market for rough diamonds, it has moved more aggressively into the marketing and retailing of polished stones.  The United States is the biggest single market in the world's $60 billion retail diamond business, and the indictment of De Beers was the last remaining obstacle preventing the company from doing business directly here. Executives have long risked arrest because of the case and have generally avoided visits.  In recent years, the company has survived a series of challenges and upheavals. In the late 1990's, De Beers managed to shrug off accusations that it had dealt in so-called blood diamonds -- illicit stones used to finance African conflicts -- and instead ended up leading a campaign to choke off the supply of tainted diamonds into the world's $8 billion rough diamond market. De Beers controls about two-thirds of the market in uncut diamonds.  At almost the same time, it began an effort to promote its diamonds more effectively through its retail clients -- called sight holders -- who buy uncut diamonds from De Beers at sales held 10 times a year in London.  Those buyers, including Americans, have long been able to sell diamonds bought as uncut stones from De Beers as polished stones in the United States. The company delisted from stock markets abroad in 2001 to return to private ownership by the Oppenheimer family of South Africa in partnership with the Anglo-American Corporation and the government of Botswana, which has a minority stake.  Alan Cowell, in Rome, contributed reporting for this article.
De Beers, world's largest diamond producer, agrees to settle criminal charges that it conspired with General Electric in 1991 and 1992 to fix world industrial diamond prices; move paves way for company to return to United States after long absence; Justice Department has been unable to prosecute company because its operations are overseas; judge threw out case against GE after trial; graph of company's market share; photos (M)