* FTSEurofirst 300 up 0.5 percent * Low trading volumes ahead of Fed, ECB * Next top riser on H1 sales boost, FY guidance hike By Tricia Wright LONDON, Aug 1 (Reuters) - European shares rose in light trade on Wednesday as investors waited to see if policymakers will back up pledges to support the euro zone with concrete measures. Markets have rallied strongly in recent days after comments by officials, including European Central Bank chief Mario Draghi, raised expectations the bank will announce steps on Thursday to ease market pressure on euro zone strugglers Spain and Italy. The FTSEurofirst 300 closed up 0.5 percent at 1,068.20, having traded in a narrow range and in volumes at 69 percent of the 90-day daily average, with investors holding back as the ECB meeting approaches. The euro zone's blue chip Euro STOXX 50 index was 0.3 percent firmer at 2,333.38. "I get the feeling from the markets and the way that they have been trading all of this week, since the (Draghi) statement, that ...people are expecting good things," Derek Hammond, head of institutional equity flows at Societe Generale, said "If he now comes and delivers something positive, there is no reason why (investors) would cut their positions in anything... People will begin to step back into the European markets." Lex van Dam, hedge fund manager at Hampstead Capital, which manages $500 million of assets, said: "We all know that the global economy is slowing and that the expectations on central banks are too high, but in the meantime most people are long cash and underweight equities which provides for support every time stocks go down." Market participants also awaited the conclusion of a two-day U.S. Federal Reserve meeting later in the day. Wall Street is braced for another round of Fed bond purchases, and some see an off chance that an announcement might come on Wednesday. Robust U.S. economic data releases on Tuesday helped give rise to a belief the Fed might stop short of aggressive measures for now, but data on Wednesday was mixed. A U.S. ADP private sector employment report showed an increase of 163,000 jobs in July, beating forecasts for 120,000 new jobs, but a U.S. Institute for Supply Management manufacturing report for July missed expectations. Given the potential for sharp variations in equity markets following the central bank decision, strategists at CM-CIC Securities in Paris recommend a 'strangle', or buying both put and call options to ensure a benefit if the index moves significantly in either direction. "If the ECB actually comes out and... confirms what's already in the markets but indicates that it's imminent, ... I think the markets might initially be disappointed that there wasn't more of a commitment there, but I think they'd be prepared to hold onto their gain," Mike Lenhoff, chief strategist at Brewin Dolphin, said. NEXT BEST THING Ahead of the ECB meeting, investors were distracted by a raft of earnings news. Next was the top riser across Europe, up 6.5 percent after Britain's second-biggest clothing retailer defied the high street gloom and beat its target for first-half sales growth. Trading volume in Next was robust, at almost three times the 90-day daily average. Shire also notched up good gains, ahead 4.8 percent, as the firm's second-quarter results beat expectations. The drugmaker's trading volume stood at just over twice the 90-day daily average. Halfway through the European results season, companies' performances are split down the middle, with 51 percent meeting or beating watered down expectations while second quarter year-on-year earnings growth is expected to have contracted around 22 percent, according to Thomson Reuters Starmine data.