The Conference Board, an industry-sponsored group, said its consumer confidence index rose to 91.5 in June from 87.2 in May. The index has a 1969-70 base of 100. The board's companion buying plans index, covering major anticipated outlays, also rose in June to 107.9 from 88.8 in May. The latest survey showed an improvement in consumer optimism about both current and future U.S. business conditions. More than 29% of the households surveyed rated current business conditions as good--up nearly one point in a month. And more than 20% said they expected business conditions to improve in the next six months; that outlook is up two points since May.