A front-page article in editions of The Washington Post last June 10 contained significant errors.

The article correctly reported that the Congressional Budget Office privately has shown Congress a preliminary forecast showing the economy is likely to fall into a full-fledged recession later this year and in 1980, with sharply rising unemployment and continued high inflation.

Details obtained by The Post showed CBO predicting that the economy's growth rate would slow to 1.3 percent in 1980, with the jobless rate rising to an average of 6.9 percent for the year. The forecast also showed inflation at 10.1 percent this year and 8.3 percent in 1980.

The forecast is more pessimistic than the one CBO issued last January, and generally is in line with those of many private economists, who also have scaled back their projections. The worsened outlook stems from several factors, including the sharp rise in oil prices.

However, three major elements of The Post's story were inaccurate:

The CBO forecast did not predict the jobless rate would rise to 7.5 percent in 1980, as The Post reported. (As a general rule of thumb, econe 7.5 percent peak was cited by some private economists whom CBO called in to review its forecast.

The CBO forecast predicted that the nation's economic output was likely to decline for two quarters, not three, as The Post rreported. (As a general rule of thumb, economists say such "negative growth" for two quarters qualifies as a recession.)

Congressional leaders were not shown the specific CBO forecast before the House and Senate voted final approval of their initial budget targets May 23, as The Post reported. They were aware of the deteriorating economic outlook but had not seen the revised forecast. The forecast was completed May 30.

The errors resulted from a misunderstanding involving sources who previously have proved reliable. The Post regrets the error.