PRECIOUS-Gold firm as U.S. healthcare vote delay weighs on stocks, dollar

* Vote on U.S. healthcare reform delayed until next month

* Dollar index touches lowest since November

* Spot silver biased to revisit December 2015 lows- technicals

(Adds quotes, updates prices) BENGALURU, June 28 (Reuters) - Gold prices firmed on Wednesday as the dollar struggled and shares weakened after a vote on U.S. healthcare reforms was postponed and European Central Bank President Mario Draghi hinted the ECB could trim its stimulus this year. Asian shares slumped on Wednesday after Wall Street was knocked hard as U.S. Senate Republican leaders delayed a vote on a healthcare overhaul on Tuesday until next month, adding to investor worries about President Donald Trump's ability to deliver on his promises of tax reform and deregulation.

The dollar index , which weighs the greenback against

a basket of six currencies, slipped to 96.322 on Wednesday, its lowest since November.

Spot gold rose 0.4 percent to $1,251.91 per ounce by

0408 GMT.

U.S. gold futures for August delivery was up 0.5

percent to $1,252.50 per ounce. "Gold prices recovered from most of the sudden plunge in prices earlier this week, with huge volumes being bought on the open in Europe," ANZ said in a note. "These gyrations point to erroneous trades, with little macro-events inducing such volatility. In the end, gold is back where it all started at around $1,250/oz," it added. The precious metal slid 1 percent on Monday as a large sell order hit sentiment, though losses were limited by political uncertainty around the world. "The dollar and the equities are on the back foot at the moment, providing a little support to gold," a Sydney-based trader said.

Wall Street's volatility index , which measures

implied volatility of stock options and is often seen as an investor fear gauge, rose nearly 12 percent on Tuesday providing some additional support, the trader added. Gold is used as an alternative investment during times of political and financial uncertainty. On Tuesday, Draghi opened the door to tweaks in the ECB's aggressive stimulus policy, fueling market expectations that the central bank will announce a reduction of stimulus as soon as September.

Among other precious metals, spot silver gained 0.7

percent to $16.78 an ounce. Silver is biased to revisit its Dec. 14, 2015 low of $13.60 per ounce over the next three months, as suggested by its wave pattern and a Fibonacci retracement analysis, according to Reuters technical analyst Wang Tao.

Platinum rose 0.6 percent to $921.60 and palladium

edged up 0.4 percent at $860.78.

(Reporting by Vijaykumar Vedala and Nithin Prasad in Bengaluru; Editing by Joseph Radford and Amrutha Gayathri)