SINGAPORE, June 21 (Reuters) - Chicago wheat futures fell on Friday and were headed for a fourth consecutive weekly loss as northern hemisphere harvests brought new supply into the market and the production outlook improved.

Corn and soybean futures steadied after dropping on Thursday as rain forecast in U.S. cropping zones eased fears that a heat wave could stress crops.

FUNDAMENTALS

* The most-active wheat contract on Chicago Board of Trade (CBOT) was down 0.2% at $5.84-3/4 a bushel at 0054 GMT, while CBOT soybeans rose 0.3% to $11.58-3/4 a bushel and corn was 0.2% higher at $4.40-1/2 a bushel.

* Wheat has tumbled from a 10-month high of $7.20 hit last month on improving weather in Russia and other major producers and the start of harvesting.

* The U.S. winter wheat harvest has seen a relatively quick beginning and a hot spell is expected to keep field work advancing this week.

* Consultants IKAR this week raised their forecast for Russia's wheat crop to 82 million metric tons from 81.5 million tons.

* An increased official forecast for Ukraine's grain crop and an analyst estimate of a record wheat crop in Romania also created expectations of large Black Sea supplies.

* In Argentina, the Buenos Aires Grains Exchange bumped up its forecast for wheat planting.

* In soybeans, China's imports from the U.S. accelerated in May with a 156% surge from a year earlier, Chinese data showed, as floods hit parts of Brazil.

* Analysts expect the government to report on Friday export sales of U.S. new crop soybeans in the week ended June 13 at 0-200,000 metric tons.

* Commodity funds were net sellers of CBOT corn, soybean, soymeal, soyoil and wheat futures on Thursday, traders said.

MARKETS NEWS

* Wall Street shares pulled back from record highs hit early on Thursday in sympathy with rallying overseas indexes, as Treasury yields shook off soft U.S. data and rose in anticipation of new supply next week. (Reporting by Cassandra Yap; Editing by Eileen Soreng)