Overall it is slanted towards liberal. And by liberal I mean, the mainstream media tends to publicize and praise opinions which favor the growth and expansion of state power over ones which favor the reducing and contraction of state power.
Just because you're a news station which favors Republicans over Democrats does not necessarily make you any more conservative. It just makes you liberal in some areas that Democrats aren't (control over substance injestion, pregnancy, more military spending, etc.) and more conservative in others.
The whole Republican = conservative and Democrat = liberal is a completely misleading idea. Both sides are liberal when it comes to central control over the currency, the use of military force overseas, the growth of government spending, etc etc.