Second-quarter earnings rose 21% from a year ago at both Aflac ( AFL) and Chubb ( CB), two insurers. At Aflac, which sells supplemental health and life insurance, net income rose 21% to $408 million, or 81 cents a share, up from $336 million, or 66 cents a share, a year ago. There were 6 cents a share of investment gains in the latest quarter, compared with a penny's worth a year ago. On an operating basis that excludes investment items, accounting adjustments and nonrecurring items, Aflac earned $376 million, or 75 cents a share, in the latest quarter, compared with $326 million, or 64 cents a share, a year ago. On this basis, analysts were forecasting earnings of 71 cents a share in the most recent quarter. Sales rose to $3.7 billion, up from $3.6 billion a year ago, as the yen weakened against the dollar. Analysts surveyed by First call were forecasting sales of $3.61 billion in this year's second quarter. Aflac does most of its business in Japan, where a weak yen hurt translations back into U.S. dollars. On a yen basis, premium income in Japan rose 6.2%, while on a dollar basis it fell 0.1% to $2.2 billion. The company said improved benefit and expense ratios boosted operating margins to 16.3% from 14.7%. The Japan unit saw total new annualized premium sales fall 4.2% in the quarter. "As we discussed at our May analyst meeting, sales in April were weaker than expected," the company said. "However, sales recovered in May and were also up for the first three weeks of June. Unfortunately, sales for the last few days of June were especially weak." "From a product perspective, the decline in second-quarter sales primarily reflected in weakness in the medical product category. Rider MAX sales and conversions were lower than a year ago, as were sales of our stand-alone medical products," Aflac said.