Dec 4 (Reuters) - A Chinese professor accused by U.S. prosecutors of helping steal American technology to benefit China's Huawei Technologies Co Ltd on Friday pleaded guilty to lying to the FBI, but is expected to be allowed to return home after prosecutors decided not to pursue a more serious charge.

The professor, Bo Mao, had been charged with conspiring to defraud Silicon Valley's CNEX Labs and faced up to 20 years behind bars. He was a visiting professor at the University of Texas when he was arrested in August 2019.

Mao, 37, pleaded guilty to the lesser charge of making a false statement in a video appearance before U.S. District Judge Pamela Chen in Brooklyn. He is expected to be sentenced to time served and leave the United States on Dec. 16. He was in custody for six days after his arrest.

Mao was originally accused of entering into an agreement with an unidentified company to use its circuit board for research and sharing the proprietary information with a Chinese company. Descriptions suggest that the first company refers to CNEX Labs and the second to Huawei.

At the plea hearing, Mao admitted through a Mandarin interpreter that he told FBI agents did not know anyone at a university in Texas owned the board. But he had sought access to one when he made the false statement.

Prosecutor Sarah Evans told the judge Mao's lies "concealed the lengths" he went to access the technology on behalf of a company she did not name, but is Huawei.

Mao's arrest came amid a U.S. Justice Department crackdown on Chinese influence in universities over alleged spying and intellectual property theft by the Chinese government.

The arrest also took place before Brooklyn federal prosecutors added trade-secret-theft charges to their 2018 indictment against Huawei, a telecommunications equipment maker.

The case against Huawei is pending in Brooklyn. In 2018, the company and its finance chief, Meng Wanzhou, were charged with misleading banks about business in Iran. The charges added in February include theft of CNEX's trade secrets. Huawei has pleaded not guilty.

In a civil lawsuit in Texas, a jury last year found Huawei misappropriated CNEX's secrets, but awarded no damages.

Meng was arrested in Canada in 2018 in connection with the criminal case. She has said she is innocent and has been fighting extradition.

Her lawyers are now in talks with the U.S. Justice Department, a person familiar with the matter said on Thursday, signaling a potential end to the case against her, which has strained ties between the United States, China and Canada. (Reporting by Karen Freifeld; editing by Jonathan Oatis, Richard Chang and Sonya Hepinstall)