(Reuters) - Brent crude slipped to $105 per barrel on Monday as economic concerns returned to the forefront on fresh fears that Spain may not be able to avoid a costly bailout, which could have repercussions on oil demand in the region.

Riskier assets including stock markets and the euro fell on Monday after tiny Murcia was on course to became the second region in Spain, the euro zone's fourth-largest economy, to request financial assistance from the central government.

Half a dozen local governments were ready to follow in the footsteps of Valencia, which on Friday said it would need help from Madrid, local media reported.

Further adding to bearishness in oil markets, U.S. demand for crude oil, gasoline and distillates fell in June from a year earlier, the industry group American Petroleum Institute said in a report.

The API attributed the drop to a slowing U.S. economy.

Brent crude was down $1.32 at $105.51 per barrel by 11.12 pm EDT, after posting a fourth straight weekly gain in the previous session.

U.S. crude fell $1.32 to $90.51 per barrel.

Oil prices had a good run up last week, so we are mostly seeing a bit of profit-taking happening with Spain back in focus, said Ben Le Brun, a markets analyst at OptionsXpress in Sydney. There is also a bit of nervousness in the market ahead of data coming out this week as things could change very quickly in the next 24 hours.

Traders are awaiting manufacturing data from China and Europe, due on Tuesday, for further clues on the health of the global economy and its impact on oil demand.

Greece, which until last month was at the centre of the euro zone debt crisis, said it was in a Great Depression similar to the United States in the 1930s, two days before international lenders arrive in Athens to push for additional cuts needed for the debt-laden country to qualify for further rescue payments to keep it afloat.

European Central Bank President Mario Draghi, however, showed confidence in the single currency, saying the euro bloc was not in danger of breaking up, judging that it was inevitably marching towards closer union among its members.

MIDDLE EAST SUPPLY CONCERNS

Concerns about potential supply disruptions in the Middle East, which drove oil prices up last week, lingered as violence in Syria intensified.

Iran has sent a new batch of enriched uranium to fuel a medical research reactor in its capital, the country's nuclear chief said on Sunday, an indication Tehran is digging in as its standoff with world powers over the enrichment continues.

Adding to supply concerns, firefighters in southeast Turkey on Saturday put out a fire on a pipeline carrying about a quarter of Iraq's oil exports, but it was unclear when oil would resume flowing, security sources said.

(Editing by Chris Lewis)