The State Duma took less than two hours Thursday to approve a raft of bills allowing the government to spend more than $18.5 billion bailing out troubled banks and supporting the plummeting domestic stock market.

Meeting in an emergency session, lawmakers overwhelmingly voted in favor of amendments to this year's federal budget, passing the changes in both their second and third readings. A law that would let the Central Bank handle corporate bonds and shares breezed through the chamber in all three readings.

The laws are part of a government rescue package worth more than $210 billion to keep the economy afloat amid major capital outflows and a crisis on the domestic credit market. Net private capital outflows may reach $20 billion this year, the Central Bank estimated recently, in stark contrast with the previous forecast of $40 billion in net inflow.

The lone dissension came from the Communists, who voted against all of the state-…