* SPDR Gold Trust holdings at 1-1/2-month high * Gold gains for a fourth straight session * Dollar slips to near three-month low * Silver hits highest level since February (Adds comment, updates prices) May 18 (Reuters) - Gold scaled a near four-month peak on Tuesday supported by a weaker U.S. dollar, while non-yielding bullion also attracted investors seeking an inflation hedge. Spot gold was up 0.3% at $1,872.20 per ounce by 1228 GMT, after hitting its highest since Jan. 29 earlier in the session. U.S. gold futures were up 0.2% at $1,871.70. “The narrative is clearly shifting towards inflation ... but perhaps more critically, you have got the U.S. dollar weakness, which is probably the key and prime driver,” said independent analyst Ross Norman. The dollar index fell to a near three-month low, making gold cheaper for other currency holders. Analysts also noted that inflows into gold exchange-traded-funds indicated that investors were buying gold to hedge against inflation worries. Holdings of SPDR Gold Trust, the world’s largest gold-backed exchange-traded fund, rose 0.7% to 1,035.93 tonnes on Monday, their highest since late-March. In the wake of rising prices in the United States, minutes of the Federal Reserve’s last policy meeting due on Wednesday are expected to provide further clarity on the central bank’s monetary policy outlook and policymakers’ views on inflation. “Fed will not be tempted to rock the boat in terms of the recovery which is gathering some momentum. Raising rates or discussion on tapering would probably be counterproductive at this stage,” Norman said. Gold is also getting support from chart-based buyers after the bullion broke above its 200-day moving average, considered to be a bullish signal. “Between $1,870 and $1,875 we’re seeing quite an important resistance zone... As long as it remains above $1,840 the trend is still bullish for bullion,” said Carlo Alberto De Casa, chief analyst ActivTrades. Elsewhere, silver climbed 1.3% to $28.53 per ounce, after hitting its highest since Feb. 2 in the session. The gold/silver ratio has dropped to around 65.5, meaning that silver has climbed even more sharply than gold, Commerzbank analysts wrote in a note. Palladium rose 0.7% to $2,922.10 per ounce, while platinum dipped 1.4% to $1,221.97. Reporting by Nallur Sethuraman, Arundhati Sarkar and Eileen Soreng in Bengaluru; Editing by Robert Birsel, Kirsten Donovan Our Standards: The Thomson Reuters Trust Principles.