Global indices are displayed on a screen on the trading floor at the New York Stock Exchange (NYSE) in Manhattan, New York City, U.S., August 19, 2021.
Global indices are displayed on a screen on the trading floor at the New York Stock Exchange (NYSE) in Manhattan, New York City, U.S., August 19, 2021. Reuters / ANDREW KELLY

Former U.S. Congressman Stephen Buyer has been charged with insider trading over purchases of shares in telecommunications company Sprint before it merged with T-Mobile US Inc, prosecutors said on Monday.

Buyer, a Republican who represented Indiana in Congress between 1993 and 2011, was working as a consultant to T-Mobile ahead of the 2018 merger, according to an indictment filed by federal prosecutors in Manhattan.

"It's always troubling whenever there's someone who has had a position of public authority... engaged in this conduct," Damian Williams, the top federal prosecutor in Manhattan, told reporters.

Andrew Goldstein, a lawyer for Buyer, said the former congressman is innocent and that his stock trades were lawful.

"He looks forward to being quickly vindicated," Goldstein said in a statement.

Prosecutors said Buyer used non-public information he learned through his consulting work to buy 112,675 Sprint shares in four brokerage accounts ahead of the April 29 merger announcement, earning a profit of about $126,000.

The next year, Buyer allegedly generated $223,000 in profit by trading in professional services firm Navigant Consulting Inc after learning non-public information it would soon be acquired by Guidehouse, his consulting company, prosecutors said.

Buyer, who was arrested on Monday, faces four counts of securities fraud over the alleged deals, and related civil charges from the U.S. Securities and Exchange Commission.

Federal prosecutors in Manhattan also announced charges against several other individuals in three other unrelated insider trading cases on Monday.