LONDON — A former trader convicted three years ago in an insider trading case has been ordered to serve additional prison time after failing to repay money obtained as a result of the trading, British regulators said on Tuesday.

The trader, Pardip Saini, was one of six men sentenced to prison in 2012 in a case that centered on inside information obtained by a former UBS employee who worked in a printing room and shared it with a group of traders. The case involved information about a variety of companies, including the Vega Group, Premier Oil and Enodis.

The group made more than 732,000 pounds, or about $1.1 million, from May 2006 to May 2008, according to the British authorities.

Last year, a criminal court in London ordered Mr. Saini to repay £464,564.91 by March 12. About £222,047.06 remains unpaid as of Tuesday, the Financial Conduct Authority of Britain said.