More than three million Latin American immigrants in the United States, responding to the economic downturn and new uncertainties about their future, have stopped sending money home to their families in the last two years, according to a survey released on Wednesday by the Inter-American Development Bank in Washington.

Only 50 percent of some 18.9 million Latino immigrants in this country now send money regularly to relatives in their home countries, compared with 73 percent two years ago, the survey found.

The drop in the number of people sending remittances, as the money transfers are known, is a sign of pressures on Latino immigrants as a result of the slump in the low-wage job market and of the Bush administration’s crackdown on illegal immigration, the survey shows. Of the immigrants interviewed, 47 percent said they did not have legal status. The others were American citizens and legal immigrants.

But while the number of immigrant senders declined, the total amount of remittances actually rose slightly between 2006 and this year, the study reported. It estimated total remittances to Latin America at $45.9 billion in 2008, an increase of $500 million over 2006. The amount did not decrease more sharply because Latino immigrants who continued to send funds home sent more money more frequently, the survey found.

However, the total amount of money transfers reported by the development bank slackened abruptly after a five-year period of huge growth in remittances to the region. Between 2001 and 2006, the amount of the transfers tripled, to $45 billion from $15 billion, according to figures from the bank, a multilateral organization based in Washington that finances development projects in Latin America.

“The longstanding pattern of increasing numbers of Latin American immigrants sending increasing amounts of money back home has stopped,” said Donald F. Terry, the general manager of the Multilateral Investment Fund at the bank and the official in charge of the survey. With lower income and less job security, Latino immigrants are saving their money here rather than sending it to support children, spouses and parents at home, the study indicated.

Latino immigrants said they stopped sending money to their families because life is becoming more difficult for them here. Of those interviewed, 81 percent said it was harder to find a good-paying job. Almost 40 percent said they were earning less this year. The largest group of immigrants in the survey, 18 percent, worked in construction, which has been especially hard hit in the slowdown.

A large majority of the Latino immigrants in the survey — whether or not they were illegal — said they experienced increasing hostility as a result of federal and state efforts to curb illegal immigration and punish employers who hire unauthorized immigrant workers. In the survey, 61 percent of Latinos who were American citizens and 66 percent of those who were legal immigrants said that discrimination had become a major problem for them.

As a result of the difficulties, the numbers of immigrants who said they were considering going back to live in their home countries increased notably. Among immigrants who have been here less than five years, 49 percent said they were thinking of returning home, while only 41 percent said they planned to remain in the United States. Over all, just under one-third of the immigrants said they were thinking of leaving this country.

In 2001, the last time a similar survey asked a comparable question, about 20 percent of all the immigrants interviewed said they were thinking of going home.

But Latino immigrant workers who participated in focus groups as part of the survey said they were not ready to leave the United States quite yet, said Sergio Bendixen, the Miami-based pollster who conducted the survey. Instead of going home, the immigrants said they were taking jobs at lower wages or sometimes working two jobs to try to maintain their income, he said.

“These are resourceful people who will do whatever job is available,” Mr. Bendixen said. “The major dynamic that is holding them back from sending money is fear. They don’t know whether they won’t be able to get a job anymore.”

Despite the worsening conditions in the United States, 69 percent of the immigrants in the survey said their financial situation was good or excellent compared with their prospects at home.

The families of an estimated 3.2 million immigrants who would lose income because they would no longer receive transfers from the United States were among the poorest in the region, and the majority were in Mexico, said Mr. Terry, the bank official.

The survey was conducted in Spanish from Feb. 9-23 with a sample of 5,000 interviews and a margin of error of 1 percentage point.

Copyright 2008 The New York Times Company. Reprinted from The New York Times, National, Thursday, May 1, 2008.