Energized by a ground-breaking foreign bribery sting, the FBI is bulking up the unit that investigates violations of the Foreign Corrupt Practices Act, a bureau official said Wednesday.

The 12-member unit is enlarging its compliment of Supervisory Special Agents from three to seven, said Andrew Sekela, one of the unit’s current SSAs, at the marcus evans 4th FCPA & Anti-Corruption Compliance Conference in Washington, D.C.

The SSAs are expected to be in place by the end of August; each will be responsible for a geographic region, from South America to Eurasia, and will oversee investigations by Special Agents in the bureau’s legal attache offices.

The hiring spree comes as the Justice Department and the Securities and Exchange Commission are marshaling resources for FCPA enforcement, and it points to an evolution of the FBI’s role in foreign bribery cases.

Just a few years ago, FCPA cases were a dull proposition for FBI agents. Most of the Justice Department’s investigations flowed from self-disclosures by companies, reducing agents’ role to taking notes in a room while prosecutors conducted interviews.

“We wanted to change that dynamic,” said Special Agent Sherri Queener, another member of the FCPA unit, who joined Sekela and other Justice Department and SEC officials for a panel discussion on recent foreign bribery cases and investigations.

About two and half years ago, agents started developing tips about widespread bribery in the military and law enforcement equipment industry. The FBI cobbled together the case with methods often associated with large-scale narcotics investigations, like Title III wiretaps and undercover agents.

“We had to figure out who these people were and put a stop to it,” Queener said.

The investigation reached a climax in January, when the FBI commenced “the Shot Show Takedown,” an operation that proved at least as sensational as its name.

Nearly two dozen industry members were arrested at a gun show in Las Vegas, the first-ever FCPA sting, and charged with participating in a scheme to bribe a sales agent who claimed to represent the defense minister of an unnamed African country. (The country, as Main Justice has reported, was Gabon; the sales agent was an undercover FBI agent.)

“What are we doing right now?” Queener said. “We are being aggressive.”

The momentum is also evident in the numbers: In 2004, the FBI had about 10 open FCPA investigations. By the end of 2009, the bureau was investigating more than 100 such matters. Sekela added that the unit is trying to farm out work to the field offices and has hosted FCPA training seminars.

Queener and Sekela said the unit’s growth was closely tied to the strength of its relationships with foreign law enforcement counterparts. In the FCPA sting investigation, for example, the City of London Police executed search warrants as FBI agents made arrests in Las Vegas.

The U.K. has been a strong partner because of existing relationships and legal treaties, but Sekela said the FBI was investing time and resources into forging new ties.

“This is just a starting point,” Sekela said, adding that the FBI hoped to host an international forum on the FCPA program.

Queener noted that the unit’s 12 agents were far flung — they’ve never been in the D.C. office at once — and were in frequent communication with Legats around the world.

“We’re everywhere, and we’re talking to people everywhere,” she said.