* Gold notches 6 pct drop in Sept, biggest in 15 months
* Dollar hits 4-year high
* Unrest in Hong Kong could hit physical demand from China (Adds comment, NEW YORK to dateline, second byline, updates market activities)
By Frank Tang and Clara Denina
NEW YORK/LONDON, Sept 30 (Reuters) - Gold fell to a nine-month low on Tuesday as the dollar surged and commodities led by crude oil tumbled on expectations of further gains in the U.S. currency.
Spot gold prices touched their lowest since Jan. 1 at $1,204.40 an ounce.
Though gold managed to recoup earlier losses, the metal is still down about 6 percent for the month with a quarterly drop of around 9 percent, marking the sharpest monthly loss since June 2013 and first quarterly loss this year.
The dollar surged to a four-year high against a basket of currencies and a two-year high against the euro on Tuesday after euro zone inflation fell in September.
Earlier this month, the U.S. Federal Reserve indicated it could raise borrowing costs faster than expected when it starts moving. A strengthening U.S. economic outlook and the dollar surge also weighed heavily on bullion’s investment appeal.
“The dollar has been the overwhelming pressure on gold in the past month, which outweighs any safe-haven concerns in the Middle East and inflation fears,” said Frances Hudson, investment director and global thematic strategist at Standard Life Investments, which manages $333.6 billion in client assets.
Spot gold was down 0.5 percent at $1,209.30 an ounce by 2:41 p.m. EDT (1841 GMT). Bullion prices partially erased losses after disappointing U.S. consumer confidence and home prices data.
U.S. COMEX gold futures for December delivery settled down $7.20 at $1,211.60 an ounce in heavy trading.
The U.S. currency has posted a record-breaking 11 weeks of successive gains, and is set for its biggest quarterly gain in six years, on expectations the Federal Reserve will raise interest rates well ahead of its counterparts in Japan and the euro zone.
A stronger U.S. currency makes dollar-denominated precious metals more expensive for holders of other currencies. Investors tend to withdraw from non-interest-bearing assets to seek higher yields elsewhere when the dollar gains.
Investors also monitor pro-democracy protests in Hong Kong, which could hit retail sales in the region, a hot spot for tourists from mainland China, especially during the one-week National Day holiday that begins on Wednesday.
Lower gold prices dragged other precious metals down, with silver fell 2.8 percent to $16.98, having earlier hit $16.83, its lowest since March 2010. It also notched its biggest quarterly loss since mid-2013.
Platinum was down 0.1 percent at $1,298.50 an ounce and set for a 12 percent quarterly drop. Palladium fell 2.3 percent to $768.10 an ounce, having touched a five-month low earlier and posted a 14 percent monthly loss, its biggest since September 2011. (Additional reporting by A. Ananthalakshmi in Singapore; Editing by Keiron Henderson, David Evans and Andrew Hay)