A former office manager for a Columbia law firm pleaded guilty yesterday to stealing almost $706,000 from the company - one of the largest embezzlement cases in county history, according to the state's attorney's office.

Christine McClain-Sloane, 41, used company checks to pay for personal expenses for six of the 11 years she worked at Nagle and Zaller PC, the Howard County state's attorney's office said.

McClain-Sloane pleaded guilty to two counts of felony theft scheme, and Howard Circuit Judge Diane O. Leasure revoked her bail. Sentencing was scheduled for March 28.

The state will ask that McClain-Sloane serve an 18- to 22-year sentence and repay the firm the $705,915, according to the state's attorney's office.

After analyzing the firm's financial and bank records, the state determined that from 1998 to 2005, McClain-Sloane wrote nearly 250 fraudulent company checks and made nearly 1,400 unauthorized personal charges to her company credit card, according to the statement of facts by Senior Assistant State's Attorney Lynn M. Marshall.

The firm's partners discovered that McClain-Sloane had stolen money after she resigned and moved to Lexington, Ky., in 2005, according to the statement of facts.

"This should be a wake-up call to any professionals and business people because what it really is, is a violation of the trust that was given to her," said P. Michael Nagle, founding partner of the firm, yesterday.

"It's really very important for businesses to have safeguards in place, which I did not have in place," he said.