* Legislation reduces spending by about $23 billion
* Liberal lawmakers decry cuts to food stamps
* Bill goes to Senate for vote as early as Thursday (Adds comments by lawmakers, details of bill)
By Eric Beech
WASHINGTON, Jan 29 (Reuters) - The U.S. House of Representatives passed a comprehensive farm bill on Wednesday that cuts payments for food stamps by about 1 percent and ends a direct subsidy to farmers, while expanding government-backed crop insurance programs.
After months of negotiations and criticism from both sides of the political spectrum the measure passed easily, by 251 votes to 166, with 162 Republicans joining 89 Democrats in favor. The bill, which is supposed to be passed every five years, is more than a year overdue after congressional negotiators struggled to forge a compromise.
A vote in the Democratic-run Senate could come as early as Thursday and the bill is expected to pass, Senate Agriculture Committee Chairwoman Debbie Stabenow told reporters on Wednesday. White House spokesman Jay Carney said President Barack Obama would sign the legislation.
The wide-ranging legislation affects about 16 million jobs in the country's agricultural sector and can have an impact on the business landscape for major agricultural companies.
"This bill eliminates unnecessary subsidies, creates a more effective farm safety-net and strengthens our commitment to conservation of land and water," Stabenow, a Michigan Democrat, said in a statement.
Stabenow was on the House floor on Wednesday and was seen hugging some members on the House floor after the vote.
The agriculture committees say the bill will save about $23 billion over 10 years, compared with current funding - less than many conservative Republicans had hoped for. The Congressional Budget Office, using a different measurement, has estimated savings of $16.6 billion over a decade.
"All Americans stand to benefit in some way from this farm bill," House Speaker John Boehner said after the vote. "This is an improvement over current law, and there are no earmarks."
About $8 billion in savings over 10 years comes from cuts to the Supplemental Nutrition Assistance Program, commonly known as food stamps. That was well below the $40 billion cut advocated by the Republican-led House, which would have been the largest reduction in a generation, but it was still double the amount originally supported by Senate Democrats.
Liberal lawmakers decried the cut of about 1 percent to the safety net program, which goes to about 47 million low-income people to buy food and accounts for more than three-quarters of the farm bill's spending.
"This bill will make hunger worse in America," Democratic Representative Jim McGovern of Massachusetts said on the House floor.
With congressional elections looming in November, Obama has highlighted social safety-net programs such as food stamps and unemployment insurance as a way to combat the widening income gap in the United States.
Conservative pressure groups Heritage Action and Club for Growth said the bill was too expensive and had urged a "no" vote. The groups said they would include the results in their scorecards of members' voting records for 2014.
The last farm bill, which passed in 2008, expired in September after being extended for one year while negotiators ironed out differences between measures approved in the House and Senate.
The legislation ends so-called direct payment subsidies, which for years have been doled out to farmers and landowners - to the tune of some $5 billion a year - regardless of whether there is a need for support and whether they actually grew crops.
Instead, agriculture insurance programs would be expanded to help producers manage risk. The bill also would establish permanent disaster assistance for livestock producers.
"We are particularly pleased with provisions to provide risk management to fruit and vegetable farmers and to support livestock farmers during disasters," the American Farm Bureau Federation said in a statement. (Reporting by Eric Beech; editing by Sandra Maler, Ros Krasny and Matthew Lewis)