LOS ANGELES, Oct 2, 2008 (AFP) - The wife of a Chinese-born US engineer jailed earlier this year for smuggling sensitive military technology to China was on Thursday sentenced to three years in prison for her role in the plot.

Rebecca Chiu Lai-wah, a 65-year-old naturalized American, was given the sentence after pleading guilty to a charge of acting as a foreign agent without informing the US government.

Under the plea deal, Chiu must relinquish her citizenship so she can be deported after completing her jail term.

Chiu's husband, Chi Mak, was in March jailed for 24 years after being found guilty in 2007 of trying to export intelligence about silent submarines in a plot that involved his wife and three other members of his family.

In court papers, prosecutor Greg Staples said the fact Chiu would be deported after her jail term made it likely that she and her husband 'will be separated for many years, if not for the rest of their lives.'

Chi Mak was convicted after being found guilty of two counts of attempting to send sensitive material to China, acting as a foreign agent without notifying the US government and making false statements to federal agents.

The engineer was arrested in October 2005 after agents swooped on two relatives at Los Angeles Airport as they prepared to board a flight to Hong Kong with a disk carrying sensitive encrypted data hidden in their luggage.

Mak's relatives, including Chiu, his brother, Tai Mak, sister-in-law, Fuk Li, and their son, Billy Mak, pleaded guilty.

Although prosecutors accused Mak of spying for China during his trial, the engineer was not formally charged with espionage because the information was not officially deemed classified.

However prosecutors said the data, which related to silent submarine technology known as the Quiet Electric Drive (QED), was extremely sensitive and was marked NOFORN, meaning it should be barred from view of foreign nationals.