Despite the dollar index falling 0.67 percent, crude oil for May delivery dropped below $85 a barrel in New York on Monday.

After European leaders offered concrete terms on loans to Greece, Oil prices started the day with an upswing.

Finance ministers of the 16-nation eurozone offered Greece $40 billion in loans, which are likely to be backed up by $20 billion in loans from the International Monetary Fund.

Silvio Peruzzo, an economist at the Royal Bank of Scotland told The New York Times that the concrete numbers were just the kind of clarification investors were looking for.

Prices turned lower Monday on concerns the United States was well supplied.

On the New York Mercantile Exchange, the price of May delivery lost 57 cents from a prior settlement to $84.35 per barrel.

Heating oil futures for May delivery slid 0.007 cents to $2.219 per gallon. With a rise of 0.0079 cents, reformulated gasoline blend-stock prices went up to $2.2972 per gallon.

After shedding 0.051 cents, Henry Hub natural gas prices ended at $4.019 per million British thermal units.

According to the reports of AAA, at the pump, the national average price for a gallon of unleaded gasoline fell to $2.86 per gallon Monday from Sunday's $2.863. (With Inputs from Agencies)