Oil prices were mixed in tight Asian trading today as dealers looked for fresh direction after the US Federal Reserve signalled it would keep its record-low benchmark interest rates on hold. 

US benchmark West Texas Intermediate (WTI) for July delivery fell 14 cents to $60.31 while Brent crude for August gained five cents to $64.31. 

Oil prices rose modestly yesterday as dealers reacted to the US Federal Reserve's decision the previous day to leave its key interest rate unchanged. 

The world's most powerful central bank said it would adopt a cautious and methodical approach to raising them later in the year. 

Interest rate adjustments are closely watched by crude investors as an increase usually leads to a pick-up in the greenback, which makes dollar-priced oil more expensive for buyers using weaker currencies and so dents demand.  

Elsewhere, investors remain concerned that top producer and leader of the OPEC cartel Saudi Arabia could boost output in an already over-supplied market, analysts said. 

The kingdom's oil minister, Ali al-Naimi, said it is ready to pump more if demand rises, Bloomberg News reported. 

It has 1.5 million to two million barrels a day of spare production capacity, al-Naimi said before a meeting with Russian Energy Minister Alexander Novak yesterday. 

Investors have previously voiced concern over the OPEC cartel's strategy of maintaining high production levels to squeeze US shale producers out of the market. 

The resulting huge global supply glut has been attributed as the main cause for oil prices collapsing by more than 50% between June and January.