SINGAPORE, July 19 (Reuters) -Middle East crude benchmark Dubai held steady on Friday, supported by purchases on the window, but spot premiums for Oman and Murban slipped.

Taiwan's CPC has bought 6 million barrels of U.S. West Texas Intermediate crude at premiums of more than $3 and $4 a barrel, traders said.

Separately, GS Caltex bought 2 million barrels of North Sea Forties crude for delivery in late September to early October at $2.50 a barrel above Dubai quotes, they added.

SINGAPORE CASH DEALS

Cash Dubai's premium to swaps was unchanged at $1.82 a barrel.

PetroChina will receive an Upper Zakum crude cargo from ExxonMobil and an Oman cargo from Vitol following the deals.

PRICES ($/BBL)

REFINERY

State-run Sinochem Group has shut two of its three east China oil refineries for an indefinite period of maintenance, as high crude oil costs and weak fuel demand hurt margins, according to trading sources and local consultancies.

Sinochem closed its Zhenghe and Changyi refineries in May and June, respectively, for indefinite overhaul periods because of poor margins, said the sources.

NEWS

Two large oil tankers were on fire on Friday after colliding in waters near Singapore, the world's biggest refuelling port, with two crew members airlifted to a hospital and others rescued from life rafts, authorities and one of the companies said.

Traders in oil, gas, power, stocks, currencies and bonds from London to Singapore struggled to operate on Friday as a global cyber outage hampered operations, companies, banks and trading sources said.

A mini OPEC+ ministerial meeting next month is unlikely to recommend changing the group's output policy, including a plan to start unwinding one layer of oil output cuts from October, three sources told Reuters.

For crude prices, oil product cracks and refining margins, please click on the RICs below.

Reporting by Florence Tan; Editing by Krishna Chandra Eluri

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