NATION'S OUTPUT FAILS TO EXPAND IN FIRST QUARTER; Estimate of Gross Product Puts It at the Same Level Reported for '66 Period RATE IS $764.3-BILLION Sales of New Cars Advance --Business Inventories Build Up at Slow Pace
Commerce Dept preliminary estimate finds 1st-qr GNP 'real' value unchanged for 1st time in 6 yrs; leveling held not to qualify as recession