Hearings on a new sugar bill began yesterday in the House with the administration and members of Congress from cane and beet states so far apart that an international agreement to stabilize world sugar prices appeared to be in jeopardy.

Howard J. Hjort, chief economist at the Department of Agriculture, told the House Agriculture Committee that he was "quite sure" that President Carter would veto a proposed 17-cents-a-pound support price bill even if that would result in the Senate refusing to ratify the international sugar pact.

That support level is contained in a bill introduced by Sen. Frank Church (D-Idaho) and cosponored by 33 colleagues. Church says that unless Carter accepts his measure or an acceptable aid program for beet and cane growers, he will not start hearings on ratification of the international sugar agreement in his Senate foreign economic policy subcommittee.

However, Hjort made clear in his testimony in the House committee yesterday that the administration views a strong stand against the bill as a test of its commitment to flight inflation.

The government wants to hold the support price at its present level of 13 1/2 cents a pound and establish a "taget price" of a minimum of 14.05 cents. The difference between the two would be covered by a government payment to growers.

Hjort told the committee that the proposed 17-cents-a-pound support would be extremely hard on foreign sugar-exporting countries and could reduce annual imports from 5 million tons to 3 million tons because the higher domestic prices would encourage more domestic growing.

He also said the administration opposed a bill that would support the most inefficient growers.

When Hjort said that it was not the administration's policy for the United States to become self-sufficient in sugar production, Rep. Ekikade la Garza (D-Tex.) exclaimed, "I hear you but I can't believe you!" De la Garza, who represents cane growers in the Rio Grande Valley, has supported a bill similar to Church's.

Rep. W. Henson Moore (R-La.) told Hjort that "nobody is producing cane for 14 cents a pound in Louisiana."

Hjort said the costs of producing sugar in this country range from 13 to 18 cents a pound, but average 15.2 cents a pound. He noted that beet and cane growers wanted a support price considerably above the production costs.

Strenuous lobbying from a wide array of commercial, consumer, foreign and labor groups is under way as the sugar bill moves through congress.

The Amalgamated Meatcutters Union, which represents some sugar refinery workers, opposes any price in creases for the sugar industry until conditions and field workers' wages improve. The field workers are NOT now organized. A substantial amount of cane sugar is grown on huge corporate plantations in Florida and Hawaii.

Arnold Mayer of the union has charged that Louisiana field workers "live on plantations in conditions similar to those existing 100 years ago - in poverty, deprivation, bad health and in debt to the company store."