Senior lawmakers from the House of Representatives and Senate are expected to announce their final compromise on the 2008 farm bill, the far-reaching agriculture law that has been inching through Congress for more than a year, later in the day.

They are expected to provide $60 million in mandatory funding for a pilot program to assess the effect of buying crops for U.S. food aid donations overseas rather than relying exclusively on U.S. farmers.

The pilot would provide far less than what the Bush administration had requested for local purchase, which could amount to more than $400 million a year based on recent budgets.

But the mandatory funding does appear to reflect lawmakers' growing concern over the skyrocketing food prices that have pitched much of the developing world into a panic.

Overhead now accounts for about 65 cents of every dollar that Food for Peace, the largest aid program, spends on food aid. Advocates of local purchase for food aid argue it will save money and deliver assistance to hungry people more quickly.

The debate comes to a head against the backdrop of sky-high, volatile global food prices, which jumped 43 percent in the 12 months ending in March.

The price surge for staples like wheat, corn, and rice is typically blamed on a potent mix of growing demand in developing countries such as China, poor harvests, and increased biofuel production.

The price crunch, which has intensified unrest across the developing world and has triggered protests and even riots in some countries, has the number of undernourished people on the rise, the World Food Program warns.

But the local purchase measure has been resisted for years by crop producers, shipping companies, and their allies on Capitol Hill, who fear it could undermine U.S. agriculture's support for food-aid programs and could even be counterproductive in countries with fragile food markets.

Lately, the Bush administration has included the measure in a handful of issues that might provoke a White House veto on the farm bill.

The farm bill may well receive a veto from Bush, who has pushed for more aggressive reform of crop subsidies and who this week said he did not support the bill.

Lawmakers are also expected to provide $90 million in mandatory funding for a program that provides meals to schoolchildren overseas.

Supporters of the McGovern-Dole program had hoped the final bill would adopt the House's decision to set $840 million in mandatory funds over five years.