The most active wheat futures on the Chicago Board Of Trade  rose 0.7 percent to $4.27-1/2 a bushel by 1122 GMT, having closed up 0.9 percent on Tuesday.

Dealers said the rise in prices this week had been driven mainly by short covering by speculators ahead of Friday's US plantings intentions report.

"It would appear that market participants are repositioning themselves in readiness for the USDA's acreage estimates on Friday," Commerzbank said in a market note.

"The figures are expected to show a significant reduction in US wheat acreage after the acreage planted with winter wheat in the autumn had decreased to its lowest level in more than a century," the bank added.

Regulatory data issued on Friday showed speculators holding a large net short position in CBOT wheat futures.

However, analysts said forecasts for wet weather across key US growing regions would likely limit support.

"There are forecasts for rains over the next three or four days, which will aid crop development. The fundamentals remain bearish," Andrew Woodhouse, grains analyst at Advance Trading Australasia, said.

EU wheat futures were mostly up with May unchanged at 166.75 euros a tonne while other positions were 0.25 to 0.75 euros higher.

The most active corn futures rose 0.6 percent to $3.60 a bushel, having gained 0.6 percent in the previous session.

The outlook for rains across the Plains, the southern Midwest and the Mississippi River Delta over the next week also threatens to delay seeding in those areas, analysts said.

The most active soybean futures were up a marginal 0.2 percent at $9.74-1/4 a bushel, having closed flat in the previous session.

Soybean gains were capped by ample global supplies, further stoked by US plantings for next season, analysts expect.

Analysts expect a 5.7 percent jump in US soybean sowings from a year ago, but have forecast a reduction in corn planting of 3.2 percent and an 8 percent cut in wheat sowings.