NEW YORK, April 24 - More warm weather gaveretail sales another boost in the latest week, with sales postingtheir longest streak of gains since the post-Christmas period lastyear and early this year, the Bank of Tokyo-Mitsubishi and UBSWarburg said on Tuesday. U.S. chain store sales rose 0.4 percent for the week ended April21, with most retailers saying they met their sales targets,compared to a 0.5 percent gain the prior week, the two firmsreported in their Weekly Chain Store Sales Snapshot. This was the first time the index had gained for three straightweeks since the Dec. 23 to Jan. 6 period. The sales index climbed to 383.2 from 381.8 a week earlier.The year-over-year index climbed 0.6 percent after remainingunchanged for two straight weeks. Some promotional activity helped fuel sales, BTM said.Continued warm weather in parts of the country helped sales ofseasonal goods such as lawn and garden supplies. Regionallysales were strongest in the East Coast and West Coast. Sales were dampened in March by unusually cool, wet weatherthroughout the month. While the number of consumers out shopping declined on theweek with many stores closed for Easter, a measure of theaverage spending by each customer jumped sharply, "suggestingthat core consumer demand remained solid for now," BTM said. BTM said it expects retail sales to rise 3 percent in April afterposting just a 1.7 percent gain in March. The BTM/UBSW Weekly Chain Stores Sales Snapshot iscompiled from about 7 major discount, department and chainstores across the country which report their weekly results.Those stores include J.C. Penney, Sears, Target, Kmart, Wal-Mart, Federated Department Stores Inc. and May DepartmentStores Co. The BTM/UBSW index measures sales growth with the year1977 equaling 100.