UPDATE 6-Oil up with Wall St, refinery problems boost gasoline

* Obama, Romney neck-and-neck as U.S. votes - polls

* S&P GSCI index to raise Brent, lower U.S. crude weighting

* Brent premium to U.S. crude nears $23/bbl intraday Tuesday

* Coming Up: API oil inventory data 4:30 p.m. EST Tuesday

(Recasts with updated prices, market activity; changes byline and dateline, pvs LONDON)

NEW YORK, Nov 6 (Reuters) - Oil rose a second straight day on Tuesday as refinery problems kept gasoline futures supported and crude oil also received a lift from stronger equities and a weaker dollar as investors awaited the result of the U.S. election.

President Barack Obama and Republican challenger Mitt Romney were neck-and-neck as Americans cast votes for president and congress, polls showed on Tuesday.

U.S. gasoline futures pushed higher as the effort to restart the New York Harbor energy network after Hurricane Sandy hit a bump on Monday when Phillips 66 said its Bayway refinery in Linden, New Jersey, will take two to three weeks to resume operations.

News that BP Plc started a crude unit overhaul at its Whiting, Indiana, refinery added support for gasoline futures and helped increase the premium of Brent to U.S. crude on the expectation it will raise crude oil stockpiles at the Cushing, Oklahoma, delivery hub for the U.S. crude contract.

``The maintenance at the Whiting refinery and the Bayway refinery remaining shut after the storm are helping push RBOB up,'' said John Kilduff, partner at Again Capital LLC in New York.

The S&P GSCI index, one of two leading commodity indices for investors, will cut the share of U.S. crude oil futures by 6.25 percentage points next year while increasing Brent by 4 percentage points, owner S&P Dow Jones Indices said late on Monday, also lending support to Brent's premium to U.S. crude.

Brent December crude rose $1.80 to $109.53 a barrel by 11:56 a.m. EST (1656 GMT), having pushed back above the 100-day moving average of $108.47.

Brent ended near 2 percent higher on Monday, rallying after falling during the session to $104.76, the lowest price since Aug. 1.

U.S. December crude rose $1.17 to $86.82 a barrel. U.S. crude also ended higher on Monday, but only after recovering from a $84.34 session low, the lowest price since July.

Brent's premium to U.S. crude increased on Tuesday, reaching $22.99 a barrel during the session.

Crude on both sides of the Atlantic had posted three consecutive weekly losses.

``The market was oversold (last week),'' Christopher Bellew, a broker at Jefferies Bache, said. ``It has been a very long move downwards from $115 down to about $105, so it's quite likely that we are going to continue upwards.''

U.S. December RBOB gasoline futures surged 5.18 cents to $2.6720 a gallon, a nearly 2 percent jump.

U.S. December heating oil , the benchmark distillate contract, rose 2.53 cents to $3.0082 a gallon.

(Additional reporting by Alice Baghdjian in London and Ramya Venugopal in Singapore)