The chief House sponsors of the railroad deregulations bill agreed yesterday to try again to breathe new life into the near-moribund measure after key administration officials pledged new support for the deregulation effort.

Rep. James J. Florio (D-N.J.), chairman of the House transportation and commerce subcommittee, said yesterday that he and Edward Madigan (R-Ill.), the subcommittee's ranking minority member, having agreed to go back to the drawing board to try to work out a compromise after Stuart Eizenstat, assistant to the president for domestic affairs, and other presidential aides paid him a visit yesterday to urge him not to give up yet.

The day before, Florio had asked House Speaker Thomas P. O'Neill Jr. to withdraw the bill from scheduled House consideration next week after failing in negotiations aimed at working out a compromise to soften the impact of a House-passed amendment that would limit the railroads' ability to raise freight rates without government interference. Florio and Madigan had withdrawn the bill from the House floor when the amendment passed last month on grounds that it ran counter to the whole thrust of the deregulation meeting.

Florio said that during yesterday's meeting, Eizenstat emphasized President Carter's commitment to having a rail deregulation bill this year if at all possible and asked him to renew his efforts. According to Florio, Eizenstat said the president was interested in "real" deregulation and had no interest in cosmetic language that will just look like deregulation. A measure that includes the controversial House-passed amendment, sponsored by Reps. Bob Eckhardt (D-Texas) and Nick Rahall (D-W.Va.), is unacceptable to the president, Florio was told.

As a result, Florio said he and Madigan will draft a measure over the weekend "that will in our opinion meet the bottom-line needs of the railroad industry and the responsible shipping community and would constitute real deregulation."

After the measure is circulated, if there is consensus that is "doable," Florio said he was told that administration, including the president personally, will seek support for it. As for its outlook, Florio said he was "neither optimistic nor pessimistic."

"I am willing to walk the next mile at the request of the administration to resuscitate the almost-corpse of rail deregulation," he said.

The bill is the last of three major administration-sponsored efforts to reduce regulation in the transportation sector. Bills that deregulate to varying degrees the airline and trucking industries already have been signed into law.

As it emerged from the House committee, the rail bill would have given the railroads significantly greater freedoms to set their freight rates without the need of Interstate Commerce Commission approval. Florio and other sponsors contend the freedom is needed if the rail industry is to begin recovering its costs.

The Eckhardt-Rahall amendment, however, would sharply circumscribe that ability. The admendment, which was adopted on a 204-to-197 vote, had widespread support from shippers who contend they are "captive" and would be forced to pay exorbitant freight rates if the railroads are given the ratesetting flexibility.

Support came from the coal producers and a major utilities that use coal, grain interests and shippers of heavy farm equipment and automobiles.