Oil prices dip below $50 on ample supply, strong dollar

Oil futures fell on Monday and US crude slipped below $50 a barrel intraday as ample supply, the prospect of more Iranian crude for export and a strengthening dollar combined to pressure prices. US refined-products futures also oscillated.

An increasing supply of refined products, especially diesel fuel being offered by Saudi Arabia, helped push US ultra-low diesel futures to multi-month lows intraday, adding to bearish concerns about prices in the oil futures complex. Brent September crude fell 45 cents to settle at $56.65 a barrel, having traded between $56.33 and $57.44.

"The dollar moved up again and the market focus is back on supply and the prospect for more Iranian exports after last week's agreement with the West over Iran's nuclear program," said Gene McGillian, analyst at Tradition Energy in Stamford, Connecticut.

A stronger dollar makes crude more expensive for investors using other currencies and rising US interest rates are expected to curb liquidity, possibly adding to price pressures on crude oil.