* Sarkozy proposed French banks roll over Greek debt
* Greece to vote on austerity measures Wednesday
* Brent's premium to U.S. oil may stay in $13-$15 range -analyst
* Coming Up: API weekly oil stocks at 2030 GMT
By Florence Tan
SINGAPORE, June 28 (Reuters) - Brent traded above $106 a barrel on Tuesday, rising for a second straight session, after a radical French proposal to roll over Greek debt strengthened the euro and eased concerns of the debt crisis spreading across Europe.
President Nicolas Sarkozy said that French banks had reached a draft agreement with the authorities on a voluntary rollover of maturing bonds, as markets anxiously awaited an outcome of a vote in Greece to approve unpopular fiscal austerity measures.
ICE Brent crude for August
"The market is slightly optimistic thanks to comments from the French President last night," said Ken Hasegawa, a commodity sales manager at Newedge Japan.
A stronger euro makes dollar-denominated oil more affordable.
Investors are still watching if Greece's parliament will approve austerity steps that are a precondition for international aid the country needs to avoid a default.
"WTI may be supported around $90, but any upside will be limited because of concerns about the economy in the euro zone," Hasegawa said.
This could keep Brent's premium to WTI
EURO GAINS
The euro inched higher on Tuesday, but stalled just below chart resistance, as investors awaited the Greek vote.
Without approval, the European Union and the International Monetary Fund say they will not disburse the fifth trance of Greece's 110 billion-euro bailout programme. Athens needs the aid to pay its bills next month and avert the euro zone's first sovereign default.
"If they fail to get an agreement, oil prices will fall," Hasegawa said.
A surprise announcement by the International Energy Agency to release oil from strategic reserves has likely been priced in after Brent fell 7 percent last week, he added.
"Fundamentally, I don't think that will have a big impact on the market ... as the 60 million barrels of oil can be absorbed easily," he said.
South Korea will start to release 3.46 million barrels of oil, including 2 million barrels of crude and 1.46 million barrels of products by "today at the earliest," a source at the economy ministry said.
A drop in prices may lift gasoline consumption in the United States, Hasegawa said, easing concerns of demand destruction at the world's largest oil user.
The market is also gearing up for a fall in crude inventories in the United States in industry data due late Tuesday. Analysts are expecting stocks to shrink for the fourth week in a row. (Reporting by Florence Tan; Editing by Manash Goswami)