News Corp has warneed that it may be facing a tough economic environment for the rest of the year, but 2008 to date has been rosy.

The media giant posted a 21% year-on-year rise in pre-tax profits for the 12 months to 30 June, boosted by a 57% revenue increase at MySpace owner Fox Interactive Media.

Revenues for the year stood at $33bn, which was up 15% from the $28.7bn reported in its 2007 financial year.

Fox Interactive Media posted revenues of $225m, which was up 23% year-on-year, and also pre-tax profits of $6m.

These quarterly revenue numbers are actually below the $233m posted in the first three months of 2008.

MySpace, and Fox Interactive Media, is the healthiest business in the company's portfolio at the moment.

News Corp's US television unit was among its weaker performers in the quarter, with pre-tax profit down 28% on the back of lower advertising revenue.

Rupert Murdoch, News Corp chairman and chief executive, said: "Although we clearly face more challenging macro-economic conditions in the 12 months between 30 June 2008 and 30 June 2009, we're well positioned to deliver continued, if somewhat less robust growth.

"Our balance sheet is strong, we have solid operating momentum in many of our key businesses and, most importantly, our assets are diversified, both geographically and along business lines, enabling us to better respond to the economic challenges we may face this year."