The Senate's current version of an economic stimulus bill offers billions more in business tax credits than the House plan does.
Both versions would allow money-losing companies to get refunds on taxes they paid on profits in previous years. But the Senate bill offers more ways to do it and that could add up to more than $15 billion in payments to those companies.
The total cost of the Senate package stands at about $890 billion, compared with $819 billion for the plan the House passed last week.
The tax packages in both are aimed at getting individuals and companies to spend money at a time when most are inclined to cut back and save. The business tax credits seek to help struggling companies stay afloat and reward companies that invest and expand.
The Senate is scheduled to begin debating its package today.