EXCLUSIVE

A former UCLA associate athletic director will have to register as a sex offender for the rest of his life ... after pleading no contest to possession of child porn.

TMZ Sports broke the story ... officials say Michael Sondheimer was in possession of child porn on his work-issued laptop in April 2013. He was charged with a felony. Sondheimer initially pled not guilty.

Now, officials say Sondheimer struck a plea deal -- in which he plead no contest and in exchange was sentenced to 3 years probation and was ordered to register as a sex offender for the rest of his life.