The Carter administration yesterday praised the thrust of trucking deregulation legislation now before a Senate committee, but said the bill doesn't move fast enough or go far enough in lifting the industry's antitrust immunity.

In testimony before the Senate Commerce Committee, Transportation Secretary Neil Goldschmidt and Associate Attorney General John Shenefield said the bill is a major step toward enacting the administration's deregulation efforts. It was introduced by Sen. Howard Cannon (D-Nev.), the panel's chairman, and Sen. Robert Packwood (R-Ore.), the ranking minority member.

Unlike legislation introduced by Carter, Sen. Edward Kennedy (D-Mass.) and others, the Cannon-Packwood measure sets a three-year transition period before removal of the antitrust immunity which permits truckers to set rates jointly.

In addition, the Cannon-Packwood bill only lifts the immunity for rates set for services offered by one carrier; the other proposal also would end antitrust immunity for rates set for services offered by more than one carrier. a

Calling the bill a "very positive step," Goldschmidt said that "prompter and stronger action to end antitrust immunity would further the effectiveness of entry reform.

"We not only want more carriers to compete in markets, we want price competition between those carriers," Goldschmidt said.

Further, Goldschmidt urged the committee to consider expanding a provision in the bill setting up a 10 percent "zone of reasonableness" level under which truckers could adjust their rates freely.

"We are not confident that a 10 percent zone will encourage individual crriers to leave the protective umbrella of the rate bureaus' immunity and prepare individual pricing initiatives," Goldschmidt told the Senate panel.

The Cannon-Packwood bill, however, drew more sweeping, if predictable, criticism from a Teamsters Union spokesman, who said the initiative behind trucking deregulation comes from "propaganda spread by college economists and bureaucrats."

A House committee also is considering a trucking measure, although it is far different from the bill before the Senate committee. The administration is expected to spell out clear opposition to the House bill Thursday.

The Senate committee, despite fierce opposition to the measure from the regulated trucking industry and the Teamsters Union, appears certain to mark up the Cannon-Packwood bill in early March.

Only one Senate Commerce Committee member, Ernest Hollings (D-S.C.), appears certain to vote against the deregulation package, although supporters of the bill believe several other senators are leaning against it.