Arnaud de Borchgrave said Monday night he will take a three-month leave from writing his weekly opinion column for The Washington Times to finish his memoirs.
The decision by Mr. de Borchgrave, a former editor of The Times and a decorated international journalist, came after an examination by two online news sites of some of his work showed similarities with material from other sources, without attribution.
"In a body of work which includes thousands of columns and news analysis over six decades, I have paid close attention to attribution, even today in an online age, when the rules for aggregators and others are changing," Mr. de Borchgrave said. "Everybody makes mistakes, and I take responsibility for mine. I will redouble my efforts to attribute with precision.
"During the next three months, however, I will take a hiatus from my column writing for The Washington Times as I complete work on my memoirs."
Ed Kelley, editor of The Times, said Mr. de Borchgrave handled the situation appropriately.
"We wish him the best during his hiatus," Mr. Kelley said.
In the meantime, The Times will conduct an internal assessment of Mr. de Borchgrave's columns, which are published on Thursdays in the newspaper and at washingtontimes.com.
Mr. de Borchgrave "has long been an asset to this organization," Mr. Kelley said. But the allegations regarding Mr. de Borchgrave's work "require attention," he said.
He gave no timetable for conducting the assessment, saying only that it would be completed "relatively soon."