The United States needs to use fiscal as well as monetary policy to boost the economy if it wants to convince cash-rich corporations to start hiring and investing, Bob Doll, chief equity strategist of BlackRock Inc said on Thursday at the Bloomberg Markets 50 Summit.

Doll, who helps manage BlackRock's more than $3.3 trillion in assets, said companies are more likely to raise their dividends or buy back shares than invest and hire because they don't know what policy to expect from Washington.

That's why I think our discussion of Fed policy has to move at some point ... to fiscal policy. It's got to go there, Doll said.

The White House recently proposed a $447 billion job creation package, but it remains unclear how much of the plan will make it through a bitterly divided Congress.

(Editing by James Dalgleish)