Asia's gasoil and jet fuel margins edged lower on Monday in the absence of most sentiment-supporting factors, with the exception of refinery maintenance, traders said. The May gasoil crack, or profit from processing a barrel of crude into the fuel, slipped 48 cents to $17.72 a barrel above Dubai crude while the jet fuel crack fell 54 cents to $15.73, Reuters data showed. The physical regrade, or the price difference between jet fuel and gasoil in Asia, widened to minus $2.32, weighed down by low demand for jet fuel, the sources said. "For the moment, there are few things to support jet fuel as the use of kerosene for heating is over," a trader said. Amid thin demand for gasoil and jet fuel in Asia, refinery maintenance in the second quarter has provided some support to the market.