* Wheat firms for first time in four sessions

* Wheat had shed nearly 4 percent in last 3 sessions

* Corn extends losses, soybeans rebound

By Colin Packham

SYDNEY, June 25 (Reuters) – U.S. wheat futures edged higher for the first time in four sessions on Wednesday, with buyers stepping in as prices hit four-month lows.

Corn slipped for the third straight session as heavy rains across key growing regions in the United States boosted expectations for a bumper crop, while soybeans rose and cut their previous session’s losses.

Chicago Board of Trade front-month wheat rose 0.4 percent to $5.73 a bushel, having closed down 1.5 percent in the previous session when it hit a four-month low of $5.70 a bushel. Wheat had shed nearly four percent in the previous three sessions.

“The market is finding support around these price levels,” said Paul Deane, senior agricultural economist at ANZ Bank. “There is perhaps some additional fund liquidation, which we have seen in recent days, to come, but the $5.70 price is a level that the market seems unable to go below.”

Wheat came under sustained pressure after the U.S. Department of Agriculture (USDA) said the rate of harvest was above market expectations.

USDA said in a weekly crop report on Monday that the harvest was 33 percent complete, despite some rain delays. That topped analysts’ estimates for 28 percent and the five-year average of 31 percent.

Front-month corn futures fell 0.2 percent to $4.42 a bushel, having closed down 0.3 percent on Tuesday.

Spot soybean futures rose 0.4 percent to $14.19 a bushel, having closed down 0.8 percent in the previous session.

November soybean futures, the most actively traded contract, rose 0.4 percent to $12.29-3/4 a bushel after closing down 0.8 percent in the previous session.

Corn has come under sustained pressure as heavy rains across the United States are expected to boost crop conditions and realise forecasts for a bumper crop.

Condition ratings for corn and soy are expected to be steady or improve next week owing to favorable weather.

The USDA last rated 72 percent of the soy crop as good to excellent, down a percentage point from the prior week because of heavy rains but higher than most analysts had expected.

Traders are expected to adjust positions in the markets before the USDA on June 30 issues separate estimates for crop plantings and grain stocks as of June 1.

The USDA will likely increase its estimate for corn seedings by 0.04 percent from March to 91.725 million acres and its estimate for soybean seedings by 0.8 percent to 82.154 million, according to a Reuters survey of analysts.

Grains prices at 0302 GMT Contract

Last

Change Pct chg Two-day chg MA 30 RSI CBOT wheat

573.00

2.00 +0.35%

-1.16%

620.05 26 CBOT corn

442.00

-1.00 -0.23%

-0.56%

459.73 39 CBOT soy

1229.75

5.25 +0.43%

-0.32%

1269.32 45 CBOT rice

$13.72

$0.03 +0.18%

-0.29%

$13.90 65 WTI crude

$106.72

$0.69 +0.65%

+0.52%

$104.25 64 Currencies

Euro/dlr

$1.360 $0.000 -0.01%

+0.00% USD/AUD

0.936

0.000 -0.03%

-0.64% Most active contracts Wheat, corn and soy US cents/bushel. Rice: USD per hundredweight RSI 14, exponential (Editing by Muralikumar Anantharaman)