Lead negotiator sees January finish for overdue U.S. farm bill

* For first time, Lucas says "next year" for farm bill

* Food stamps is central issue in long-delayed legislation

* Lucas goal: a farm bill framework now for a vote later

* Republicans see more chances to chip away at food stamp costs

WASHINGTON, Dec 3 (Reuters) - Congress could enact a new U.S. farm law that cuts food stamps for the poor and expands federally subsidized crop insurance in January if negotiators soon break a deadlock, the lawmaker overseeing the negotiations said on Tuesday.

Cuts in food stamps are the paramount issue for the farm bill, which is more than a year overdue. Conservative Republicans want the largest cuts in a generation, $40 billion over 10 years. House Democrats solidly oppose any cuts. The sides continue to struggle for a compromise.

The food stamp fight has repeatedly slowed work on the five-year, $500 billion bill, which has also endured the first-ever defeat of a farm bill in the House of Representatives. Deep divisions also remain over crop subsidies and dairy reform, other lines of dispute that must be resolved.

With time running out in 2013, Frank Lucas of Oklahoma, who chairs the House-Senate negotiations, admitted for the first time that the farm bill may not be ready for a vote before year-end, even though a broad framework might be hammered out this month.

"We're not quite there yet," Lucas, chairman of the House Agriculture Committee, said on the AgriTalk radio program, which is broadcast across a wide swathe of the central United States.

"It is possible to have an understanding, a set of principles laid out, a text that the lawyers could work on with the economists to complete so we'd be back next January to finish the final job," Lucas said.

The "big four" agricultural negotiators - Lucas, Senate Agriculture chairwoman Debbie Stabenow, Rep. Collin Peterson of Minnesota and Sen. Thad Cochran of Mississippi - agreed to meet on Wednesday in search of a breakthrough. Two days of face-to-face talks foundered in late November.

"We've had this uncertainty for far too long. It's time for Congress to finish its work," Agriculture Secretary Tom Vilsack told reporters on Tuesday.

But Vilsack dismissed the idea the White House and congressional leaders should take over the stalled talks, as did House Speaker John Boehner at a news conference.

The Senate's farm bill would cut food stamps by $4.5 billion over a decade, mostly by narrowing a loophole on utility costs. House Republicans proposed tighter eligibility rules that would end benefits to about 4 million people in 2014. Some 47.7 million people received food stamps at latest count - about one in seven Americans.

On Tuesday, two Republican aides said Stabenow was unwilling to consider reforms that were good policy and would save money. The utility loophole could be tightened further to generate $9 billion in savings, for example, they said.

"It sounds academic, so abstract," said Ellen Vollinger, legal/director of the anti-hunger group Food Research and Action Center. But ultimatedly lower funding "comes down to food dollars," she said.