An employee who sabotaged Citibank's computer system because he believed he was about to be fired has been sentenced to nearly two years in prison.

Investigators say Lennon Ray Brown of Dallas transmitted a code and command in 2013 leading to loss of connectivity to 90 percent of Citibank networks in North America.

Brown was sentenced Monday to 21 months in federal prison and fined more than $77,000. The 38-year-old Brown pleaded guilty in February to intentional damage to a protected computer.

Investigators say Brown caused the damage after a discussion with a supervisor about his work performance at the Citibank Regents Campus near Dallas in December 2013.

Brown later texted a co-worker saying he was about to be fired from Citibank and had "beat them to it."