(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window.) * Salesforce rises on strong Q2 results, upbeat forecast * U.S. dollar stores slip as freight costs hit profit forecasts * Indexes down: Dow 0.25%, S&P 0.30%, Nasdaq 0.22% (Updates to late afternoon trade, changes dateline, byline) NEW YORK, Aug 26 (Reuters) - Wall Street headed lower on Thursday, on track to snap a winning streak of all-time closing highs as mixed economic data and concerns over a potential shift in U.S. Federal Reserve policy prompted a broad but shallow sell-off a day ahead of the Jackson Hole Symposium. All three major U.S. stock indexes extended their declines after hawkish commentary from Dallas Fed President Robert Kaplan and a blast outside the Kabul airport in Afghanistan helped fuel the risk-off sentiment. Kaplan, who is not currently a voting member of the Federal Open Markets Committee, said he believes the progress of economic recovery warrants tapering of the Fed’s asset purchases to commence in October or shortly thereafter. Kaplan’s remarks followed earlier comments from the St. Louis Fed President James Bullard, who said that the central bank is “coalescing” around a plan to begin tapering process. “There’s a lot of focus over what will come out of Jackson Hole meeting,” said Bill Northey, senior investment director at U.S. Bank Wealth Management in Minneapolis. “Whether we will see new information regarding inflection point in (Fed) policy or whether that will be deferred to the next meeting in September.” Regarding the recovery, the economy grew at a slightly faster pace than originally reported in the second quarter, fully recovering its losses from the most abrupt downturn in U.S. history, according to the Commerce Department. But jobless claims, though still on a downward trajectory, ticked higher last week. For an interactive GDP graphic, click here here. The data did little to move the needle with respect to expectations that the Fed is unlikely tip its hand regarding the taper timeline when Chairman Jerome Powell unmutes and delivers his speech at Friday’s virtual Jackson Hole Symposium. “We’re transitioning between two horizons, the first being the reopening of the economy,” Northey added. “There’s little question that the data is strong across the U.S. economy. “Horizon two is when we get back to economic normalization,” he continued. “There’s concert about the Delta variant extending the timeline between horizon one and horizon two.” The Dow Jones Industrial Average fell 89.35 points, or 0.25%, to 35,316.15, the S&P 500 lost 13.6 points, or 0.30%, to 4,482.59 and the Nasdaq Composite dropped 33.42 points, or 0.22%, to 15,008.44. Of the 11 major sectors in the S&P 500, all but real estate were in the red, with energy stocks suffering the steepest percentage loss after several sessions of strong gains. Discount retailers Dollar General Corp and Dollar Tree Inc tumbled 3.8% and 11.9%, respectively, after warning higher transportation costs will hurt their bottom lines. Coty Inc jumped 14.8% after the cosmetics firm said it expects to post full-year sales growth for the first time in three years. Salesforce.com Inc hiked its earnings forecast as the shift to a hybrid work model is expected to fuel strong demand. Its shares advanced 4.9%. NetApp Inc jumped 5.6% as brokerages raised their price targets in the wake of the cloud computing firm’s better-than expected 2022 earnings outlook. Declining issues outnumbered advancing ones on the NYSE by a 2.29-to-1 ratio; on Nasdaq, a 1.44-to-1 ratio favored decliners. The S&P 500 posted 29 new 52-week highs and two new lows; the Nasdaq Composite recorded 74 new highs and 33 new lows. (Reporting by Stephen Culp; Additional reporting by Devik Jain in Bengaluru Editing by Marguerita Choy) Our Standards: The Thomson Reuters Trust Principles.