Key House sponsors of a railroad deregulation bill will not bring up the measure again unless they are reasonably certain they can turn around last week's vote to significantly limit the rails' ability to set freight rates without government interference, one of them said yesterday.

"We have met and decided we will not be part of the process to worsen the well-being of the railroads," Rep. James J. Florio (D-N.J.) said yesterday. Florio, chairman of the subcommittee on transportation and commerce, and Edward R. Adigan (R-Ill.), the subcommittee's ranking minority member, are the chief House sponsors of the measure.

Florio withdrew the bill from the House floor last week after an amendment circumscribing the rate-setting freedomes the bill would give the railroad industry passed on a vote of 204 to 197. Sponsored by Reps. Bob Eckhardt (D-Texase and Nick Rahall (D-W. Va.), the amendment would retain Interstate Commerce Commission jurisdiction if a railroad increased rates above a certain level. The amendment had the support of the shippers of coal, grain, heavy farm equipment and other commodities who contend they are "captive" or isolated and will be forced to pay exorbitant freight rates if the railroads are given rate-setting flexibility.

Florio says a number of congressmen who voted for the amendment have come to him since saying that they would vote with him if they had another chance, that they now understand that the Eckhardt-Rahall amendment eliminated many provisions of the bill that worked to their benefit. If a consensus evolves, Florio said, the bill will be brought up again after Congress returns from the two-week Democratic Convention recess.

Florio also released a letter from ICC Chairman Darius W. Gaskins Jr. who lamented that the bill as amended does not give railroads sufficient pricing flexibility. Without the Eckhardt amendment, Gaskins wrote, the bill "provided a balanced approach to solving the railroads' financial prolems while at the same time guaranteeing shippers protection from abuses of the marketplace."

On the critical issue of rate making, Gaskins said the bill as amended would freeze existing commission practice instead of taking a step forward. The amendment's prohibition on the use of demand-sensitive rates to a broad category of agricultural commodities is "a significant step backward," Gaskins said.

"This letter is evidence of the truth of the basic proposition we made -- that the bill as amended by Mr. Eckhardt results in much more regulation than exists now," Florio said.

At a press conference yesterday, Eckhardt called the Florio bill "special-interest legislation" while describing his amendment as a "national solution" even though it helps significantly several large Texas utilities that use coal.

Eckhardt also disputed the contention of Consolidated Rail Corp. that passage of the amended bill will effectively end whatever prospects Conrail has to survive and succeed as a private-sector railroad.