Oil fell below $50 a barrel on July 5 on concerns that a potential slowdown in economic growth could sap demand and persistent signs of abundant supply despite another militant attack on Nigeria's oil industry.

Trade in one of Britain's largest property funds was suspended in a sign of financial stress following the country's vote to leave the European Union (EU). A flurry of data from China in the coming weeks is expected to show weakness in trade and investment.

Brent crude was down $1.21 at $48.89 a barrel at 6:40 a.m. CT (11:40 GMT). The global benchmark is still up more than 80% from a 12-year low close to $27 reached in January. U.S. crude was down $1.35 at $47.64 a barrel.

"Asia has been relatively weak and China is not providing much support," said Olivier Jakob, oil analyst at Petromatrix, who also said weak refined products were pressuring crude.

"Without the support of the products and with a structure in crude oil that is weakening, it is difficult to think that crude can break away to the upside," he said.

British bank Barclays said concern over the global economy was weighing.

"The deterioration in the global economic outlook, financial market uncertainty and ripple effects on key areas of oil demand growth are likely to exacerbate already-lacklustre industrial demand growth trends," the bank said in a report.

Oil has gained support this year from the perception that a supply glut that has halved oil prices in the last two years may be easing, and from unplanned outages from Canada to Nigeria. But signs of ample supply of crude and products persist.

A partial recovery in Nigeria contributed to a rise in OPEC crude production last month, a Reuters survey found last week. Several tankers carrying gasoline-making components have dropped anchor off New York harbor, unable to discharge as onshore tanks are full.

In Libya, where oil output has slowed to a trickle due to conflict, the National Oil Corp. has agreed to merge with its domestic rival, raising hopes the OPEC country could start to pump more.

"Further downward price pressure is expected as signs of an oversupplied global market refuse to go away," said oil broker PVM, adding that "macro-economic risk" was scaring buyers away.

Another attack in Nigeria had a limited impact on prices.

A militant group that has been carrying out attacks on the country's oil installations said on July 5 it blew up a well and two pipelines, having claimed responsibility on July 3 for five other attacks.