Publisher and one-time GOP presidential hopeful Steve Forbes blasted Fortune magazine for questioning the financial health of his own publication, telling employees in an email that Fortune has ulterior motives.

"Today Fortune magazine published a story on Forbes with the clear intention of disrupting the business of its most formidable competitor," Forbes says in his email, obtained by All Things D, a Wall Street Journal Publication.

"Fortune was aware that this was highly confidential, private information and of no value to release to the public. Though the intention is to harm our business, it will not adversely impact Forbes because it highlights a very difficult time in the past when all the media industry was going through unprecedented upheaval."

The company, meanwhile, is in good financial shape, he says.

"Forbes is profitable and is successfully navigating these extraordinarily turbulent seas. The company continues to grow and thrive with powerful new strategies and talent."

Fortune, a global business magazine published by Time Inc.'s Fortune Money Group, didn't hold back in its critique of Forbes.

"According to nonpublic documents made available to Fortune, the company has been under more financial strain than previously believed. Forbes Media violated covenants on a revolving credit line that it took out in 2006, according to a letter sent to the company by J.P. Morgan. The loan, which was part of a series of transactions that allowed the Forbes family to cash out more than $100 million from the company, is due next July. Some lenders have been selling pieces of it at a discount from face value," Fortune reports.