* Gold chops back and forth to the tune of the dollar
* Hurricane Ike supports oil prices, underpinning gold
* U.S. bailout impact on commodities still uncertain
(refreshes throughout)
By Anna Stablum
LONDON, Sept 8 (Reuters) - Gold swung back and forth on Monday, twice rising 2 percent before partially relinquishing the gains, tracking moves in the dollar and oil prices.
Analysts digested the impact on commodities from a U.S. bailout of two top mortgage lenders, which may encourage investors to return to riskier assets.
"The dollar is at the fore ... if we see the dollar break below $1.42 to the euro then gold will go swiftly under $800 an ounce again," said analyst Tom Kendall at Mitsubishi.
Spot gold <XAU=> extended gains into a second session to stand at $810.50 per ounce by 1412 GMT, up from $801.10 in late New York trade on Friday. Prices twice visited the day's high of $818.00 but failed each time to make further headway.
Traders said the market was choppy and thin volumes were helping to exaggerate price moves.
Gold hit a year-to-date low of $773.90 on Aug. 15.
Earlier in the session gold was buoyed by the euro's <EUR=> gains against the dollar, rising to around $1.4430, off an 11-month low of $1.4197 touched last week. It was last quoted at $1.4204.
The dollar initially fell in the aftermath of the weekend action as investors took the government's takeover of the stricken mortgage agencies as an excuse to pile back into riskier assets.
Crude oil <CLc1> rose to over $109 a barrel, rebounding from a five-month low as Hurricane Ike spun twoards the U.S. Gulf of Mexico oil hub.
"Today the atmosphere in the gold market is somewhat positive again with oil prices seeming to stabilise a bit," said Alexander Zumpfe, trader with Heraeus Metallhandelsgesellschaft.
He noted good physical demand notably from retail investors.
Gold generally is seen as a hedge against oil-led inflation and often moves in the opposite direction of the dollar as it becomes cheaper for investors holding other currencies.
Some analysts said gold's bounce on Monday appeared more likely to be cautionary short-covering after a tumble from nearly $1,000 an ounce in mid-July.
The outlook for gold remained bearish, but it could gather safe-haven appeal with the outlook for the U.S. currency and the economy unclear, traders said.
The market needed more time to see the impact of the U.S. government's action regarding the two U.S. mortgage giants.
"It is a reason to be less bullish on the dollar, but not bearish," Kendall said, adding that the knock-on effect on commodities could be brief.
A firm U.S. currency makes dollar-priced commodities more expensive to holders of other currencies and tends to cap prices.
The U.S. government acted on Sunday to seize control of mortgage finance companies Fannie Mae <FNM.N> and Freddie Mac <FRE.N>, in a move that may temper the global financial market turbulence that has threatened economic growth. [
]Silver <XAG=> was firmer at $12.35/12.40 against $12.19/12.27 in New York on Friday when it hit its lowest level in a year, prompting buying from industrial consumers and investors.
"Silver has been oversold relative to gold and that is giving it a touch of support ... otherwise the market is mostly taking its direction from gold," Kendall said.
Platinum <XPT=> strengthened to $1,357.50/1,377.50, up from Friday's last quote of $1,353.00/1,373.00. Palladium <XPD=> was little changed at $266.50/274.50 from $267.00/275 in New York. (Additional reporting by Clare Black, editing by Hans Peters)