May 20 (Bloomberg) -- Argentina's four biggest farm groups plan to suspend a national strike at midnight in a bid to revive talks with the government over tax increases that have disrupted the country's grain exports.

Farmers said they will halt roadblocks and protests that began May 7 and will encourage the government to find ``concrete solutions'' to resolving the two-month dispute, which has undermined support for President Cristina Fernandez de Kirchner's five-month-old administration.

``We want to create an environment for negotiations to take place,'' Eduardo Buzzi, president of the Agrarian Federation, told reporters in Buenos Aires last night. ``We can't be out in the roads indefinitely.''

Farmers began demonstrating after the government announced a new variable export tax on grains and oilseeds on March 11. Roadblocks in March and early April led to food shortages across Argentina and prompted the biggest anti-government protests since 2001. A one-month truce called April 2 expired without an accord, spurring a new round of protests this month.

The farm groups said they will contact government ministers today to arrange a meeting. Buzzi said protesters will remain ``on alert'' as talks proceed and are planning a rally in the agricultural city of Rosario on May 25, when the country commemorates the 198th anniversary of the revolution that led to Argentina's independence from Spain.

Argentina is the world's third-largest soybean exporter behind the U.S. and Brazil, and the second-largest corn exporter after the U.S.

Prices Fall

Soybean futures fell the most in two weeks yesterday and dropped again today on speculation the strike would end. The July contract fell 1.5 cents, or 0.1 percent, to $13.315 a bushel in trading on the Chicago Board of Trade.

``We hope this decision generates a reciprocal response on the part of the government to immediately resolve this dispute in a climate of peace and harmony,'' the four farm groups said in a statement e-mailed to reporters last night.

The new tax system announced March 11 levies soybeans and sunflower seeds at more than 40 percent, depending on market prices, compared with a previous fixed rate of 35 percent. President Fernandez said the taxes will curtail inflation and allow the government to maintain a competitive exchange rate.

Opposition lawmakers met in Congress today to propose changes to the export-tax regime. They were outnumbered by empty seats normally taken by the pro-government majority.

Declining Public Support

The dispute with farmers has helped cut Fernandez's popularity almost in half, to 23 percent who view her favorably from 42 percent when she took office in December, pollster Jorge Giacobbe said, citing a survey of 1,000 Argentines between April 30 and May 13. Fernandez is the most unpopular Argentine president since Fernando de la Rua raised taxes in 1999, Giacobbe said. De la Rua quit two years later amid a financial crisis.

``This conflict has provoked terrible tensions in the country,'' opposition lawmaker Francisco Ferro said in Congress today in comments broadcast on national television.

Economy Minister Martin Lousteau resigned April 24 as talks between the government and farm groups foundered. He was replaced by Carlos Fernandez, the former head of the country's tax agency, who was sworn in the following day.

To contact the reporter on this story: Bill Faries in Buenos Aires at wfaries@bloomberg.net

Last Updated: May 20, 2008 16:59 EDT