Yahoo has announced a pre-tax loss of $303m in Q4 2008.

This is tough news for the company’s latest chief executive, Carol Bartz, who has insisted the company is not for sale despite the bad results.

Bartz, who replaced Jerry Yang, says she was not hired simply to sell all or part of Yahoo to Microsoft. Bartz did not indicate what she had planned for the search engine but supports its decision to freeze the pay of its 13,700 employees.

A number of high profile deals between the two companies broke down in late 2008, however, with burgeoning debts and the financial crisis looming, it is possible that Yahoo may revisit the Microsoft deal.

Company spokespeople believe that declining online ad sales was the key cause of its first revenue drop since the dot.com bust earlier this decade. Revenue was $1.8bn in Q4, a 1% decrease compared to $1.83bn for the same period of 2007.

International revenue was $468m, a 10% decrease year on year, with US revenue at $1.3bn, a 2% increase year on year.