LOS ANGELES  California, the nation’s most populous state and the world’s sixth-biggest economy, has warned the Treasury Department that it may need a $7 billion emergency loan from the federal government because it is running out of cash and has not been able to borrow more.

State officials said they hoped that the $700 billion federal bailout of the financial system approved by the House of Representatives on Friday would help open credit markets that have balked at providing the kind of short-term financing California and other states and local governments routinely rely on to keep operating.

But Gov. Arnold Schwarzenegger, a Republican, said at a news conference on Friday that the state “is not out of the woods yet” and in a few weeks could run out of cash to pay for basic services.

Mr. Schwarzenegger had sent a letter on Thursday night to Treasury Secretary Henry M. Paulson Jr., warning that the state might be forced to seek the emergency loan.