Congress has approved another extension of federal highway funding, giving lawmakers until July 31 to find a compromise on a new six-year spending plan, news services reported.

This is the fourth time Congress has extended funding since the original $218 billion legislation expired Sept. 30, 2003. President Bush has said he favors a $256 billion plan, but the House approved a $283 billion plan on April 2 and the Senate passed a $318 billion proposal Feb. 12.

Meanwhile, House Majority Leader Tom DeLay, R-Texas, said the Senate's proposed funding for a $318 billion highway bill is based on phony math and would increase taxes on American businesses.

"The $318 billion in the Senate bill just doesn't add up," DeLay said. "Instead of creating a fiscally responsible highway bill, the Senate is using it as a slush fund to rob other programs and raise taxes. It's not going to happen."

The Senate passed the extension by voice vote while the House voted 418-0 for it.

Bush has threatened to veto any bill higher than the $256 billion he was seeking, but Don Young, R-Alaska, chairman of the Transportation Committee, said he would remain firm on at least $275 billion during talks with the Senate on a final bill, Reuters reported.

"The Senate bill is begging for a veto," DeLay said. "We must rely on more jobs and more economic growth to fund our highways, not new tax increases."