A former associate in the fixed income research division at Goldman Sachs & Co. was sentenced on Thursday to 57 months in prison for his role in an international insider-trading network.

Eugene Plotkin, a native of the former Soviet Union who pleaded guilty in August, was accused of running a series of schemes that resulted in more than $6.7 million in illegal gains, according to Michael Garcia, the U.S. Attorney for the Southern District of New York. Garcia says Plotkin sought to illegally trade on inside information from a number of sources, including college friend Stanislav Shpigelman, an analyst at Merrill Lynch.

Plotkin also worked with Nickolaus Shuster and Juan Renteria, two employees of a Wisconsin printing plant who stole advance copies of BusinessWeek to provide Plotkin with prepublication information from the magazine’s “Inside Wall Street” column. In addition, Plotkin partnered with Jason Smith, who, while serving as a federal grand juror in New Jersey, passed along information about the accounting investigation of Bristol-Myers Squibb Co.

Shpigelman, Shuster, Smith, Renteria, and David Pajcin, a onetime Goldman analyst who played a central role with Plotkin in the insider-trading schemes, have all since pleaded guilty to insider-trading charges.

According to reports, Plotkin introduced Pajcin to Shpigelman in 2004 at a Russian day spa and sauna in lower Manhattan, notes the Associated Press. Plotkin and Pajcin obtained inside information from Shpigelman, who at the time was working as an investment-banking analyst in Merrill Lynch’s merger-and-acquisition division. In exchange for cash payments and promises of future payments based on a percentage of profits, Shpigelman provided Plotkin and Pajcin with nonpublic information on six different pending mergers or acquisitions being handled by Merrill Lynch, some of which Shpigelman had worked on directly.

This allowed Plotkin, Pajcin, and others with whom they shared the information to purchase securities based on knowledge of the deals prior to the public announcement of the transactions. The individuals then liquidated those positions after the public announcement, which triggered a rise in the stock prices.

At the same time Plotkin and Pajcin were trading on the Merrill Lynch deal information, the duo bribed Shuster and Renteria, the printing plant workers, to steal the names of stocks touted in the “Inside Wall Street” column from unpublished BusinessWeek magazines. The two plant workers provided Plotkin and Pajcin with the information one trading day before the column was available to the public. In total, the scheme allowed the two former bank analysts to trade in about 20 different stocks a day before the favorable reviews appeared in the magazine. Plotkin and Pajcin then sold those stocks for a profit after the column’s review caused the prices of the stocks to climb.

In addition to the 57 months in prison, Plotkin was ordered to pay a $10,000 fine and forfeit $6.7 million, representing the proceeds from his insider-trading schemes. According to The New York Journal News, Plotkin defense lawyer Edward J.M. Little argued in court papers that Pajcin came up with idea of gaining inside information and using it to make trades after meeting with “criminal types” in Croatia.

Little reportedly portrayed Pajcin as the mastermind of the criminal acts and said Ploktin was motivated by a desire to preserve his friendship with Pajcin. The defense attorney told the court that Plotkin was depressed over not having many friends, according to the Journal News. Little said Pajcin was a “charming and good-looking man who was particularly effective with women, and he filled a void in Gene [Plotkin]’s life.”

While criminal insider-trading cases make headlines, civil suits are causing a stir at the Securities and Exchange Commission enforcement division. The SEC filed 14 percent more insider-trading enforcement cases in 2007 than in the year before, according to Bloomberg. Out of the 656 cases brought by the SEC in 2007, 47 involved insider trading — 1 more case than in 2006.

The regulator is also paying close attention to 10b5-1 plans that protect executives from insider-trading accusations by allowing them to sell stock automatically at prearranged intervals. Furthermore, the SEC has cracked down on several so-called pillow-talk cases by settling insider-trading charges that spouses or relatives illegally shared confidential information about a company. At least one case involved a father and son, who later settled SEC charges of illegal insider trading involving securities of three public companies.