(Adds details, share move)
Aug 24 (Reuters) - Dollar Tree Inc reported better-than-expected quarterly profit and comparable sales, helped by lower costs and discounts as well as a 1 percent rise in same-store sales at its Family Dollar business. Shares of the biggest U.S. dollar-store chain operator were up 9 percent in premarket trading on Thursday.
The 1 percent rise in sales at Family Dollar stores in the second quarter came in above the 0.6 percent rise expected by analysts.
Family Dollar, which Dollar Tree bought in 2015, had reported a surprise drop in sales in the first quarter as late tax refunds had led low-income customers to rein in spending at the discount chain's stores.
Sales at Dollar Tree's stores open more than 12 months rose 2.4 percent, above the 1.6 percent growth expected by analysts polled by research firm Consensus Metrix.
Net income rose to $233.8 million, or 98 cents per share, in the second quarter ended July 29, from $170.2 million, or 72 cents per share, a year earlier.
Excluding items, the company earned 99 cents per share, handily beating the average analyst estimate of 87 cents per share, according to Thomson Reuters I/B/E/S.
Net sales rose 5.7 percent to $5.28 billion, coming in above the $5.24 billion expected by analysts.
(Reporting by Sruthi Ramakrishnan in Bengaluru; Editing by Arun Koyyur)