PARIS/MANILA, April 5 (Reuters) - Chicago wheat, corn and soybean futures eased again on Wednesday as weather for U.S. spring planting was forecast to improve in the coming days, analysts said.

The prospect of a drier, warmer spell helping field work took attention away from poor conditions for drought-affected winter wheat in part of the U.S. Plains.

The fading of a crude oil rally and investor concerns about the economic outlook also capped grain prices as participants adjusted positions in the run-up to a holiday weekend.

Planting in the U.S. Midwest and Delta should accelerate next week, while the melting of snow in the northern Plains should also help field work next week, the Commodity Weather Group (CWG) said in a note.

The U.S. Department of Agriculture said the U.S. corn crop was 2% planted by Sunday, in line with the five-year average.

The most-active wheat contract on the Chicago Board of Trade (CBOT) was down 2% at $6.77-3/4 a bushel by 1226 GMT.

CBOT corn was down 0.9% at $6.47-3/4 a bushel, while CBOT soybeans edged 0.6% lower to $15.08-1/4 a bushel.

South American crops also remained a focus, with a bumper Brazilian soybean harvest expected to offset a drought-hit Argentine crop.

Argentina is set to lose its status as the world's top exporter of processed soymeal due to the historic drought, according to the Rosario stock exchange.

Rains expected this weekend in northern Brazil could help reduced dryness for developing corn crops, CWG said.

(Reporting by Gus Trompiz in Paris and Enrico Dela Cruz in Manila; Editing by Sherry Jacob-Phillips and Sharon Singleton)