By Mengqi Sun 

A Chinese national was sentenced to two years in prison for allegedly stealing proprietary information worth about $1 billion from his Oklahoma employer, the U.S. Justice Department said Thursday.

Hongjin Tan, 36 years old, is a Chinese citizen and U.S. legal permanent resident. He pleaded guilty in federal court in Oklahoma in November to charges including theft, unauthorized transmission and unauthorized possession of a trade secret.

Mr. Tan, who was arrested in December 2018, stole the information from a petroleum company in Oklahoma, prosecutors said.

A lawyer representing Mr. Tan didn't immediately respond to a request for comment.

The Justice Department didn't identify Mr. Tan's U.S. employer. A LinkedIn profile for a Hongjin Tan listed experience as a staff scientist at Phillips 66 in Bartlesville, Okla., starting in May 2017.

A representative for Phillips 66 declined to comment, citing company practice to not comment on legal matters.

Mr. Tan used a personal thumb drive to copy hundreds of files, including information that the company considers to be trade secrets and that was outside of his area of responsibility, prosecutors said. He also downloaded files onto an external hard drive that was later found at his home, according to prosecutors.

On Dec. 12, 2018, the day after copying the files, he turned in his resignation from the company. He told his supervisor he was returning to China to care for his aging parents and didn't have a job offer, but was negotiating with a few battery companies in China, prosecutors said.

A hiring agreement written in Chinese from another organization was later found on Mr. Tan's work laptop, prosecutors said. The letter, dated Oct. 15, 2018, offered him a director position in Xiamen, China, according to the complaint.

A federal judge in Oklahoma also ordered Mr. Tan to pay $150,000 in restitution to his former employer.

Write to Mengqi Sun at mengqi.sun@wsj.com

(END) Dow Jones Newswires

February 27, 2020 18:45 ET (23:45 GMT)