NEW YORK (Reuters) - A 22-year-old California man pleaded guilty on Thursday to hacking into the New York Times Co. computer network and entering a database containing personal information about Op-Ed page contributors.

Adrian Lamo, who turned himself in to federal authorities in Sacramento, California in September, pleaded guilty to one count of computer damage causing more than $5,000 in losses to the New York Times.

Under a plea deal reached with federal prosecutors, Lamo agreed to serve a prison term of between six months and one year. However, it will be up to the judge to determine his punishment during a sentencing hearing set for April 8.

"I knew I crossed the line...I am genuinely remorseful," he said during his plea hearing in Manhattan federal court.

The charge accuses him of hacking into the New York Times internal computer network between February and April of 2002 and accessing a database containing personal information including home telephone numbers and Social Security numbers for over 3,000 contributors to the newspaper's Op-Ed page.

After accessing the system, Lamo entered his name, his cellular telephone number (415) 505-HACK, and a description of his areas of expertise as "computer hacking, national security, communications intelligence."

While inside its internal network, Lamo had set up five fictitious user identification names and passwords under the New York Times' account with LexisNexis, an online subscription service that provides news and other information for a fee. LexisNexis is owned by Anglo-Dutch media conglomerate Reed Elsevier .

Prosecutors said Lamo used those names to conduct more than 3,000 searches on LexisNexis with some of those searches for news stories about himself. When he was first charged in September, authorities said he ran up some $300,000 in bills.

In February, Lamo had admitted on a Web site, SecurityFocus.com, that he had broken into the New York Times network and described in detail how he carried out the intrusion, prosecutors said.

According to the government, he has also admitted other intrusions in print and on-line articles including entering networks of such large corporations as Microsoft Corp. Cingular Wireless and Yahoo Inc.