Oil prices rose and stocks were down slightly on Sunday as hopes were dashed for a breakthrough in the standoff over the Strait of Hormuz.

At the end of last week, Iran and Oman indicated that they were near an agreement that would allow oil and other important commercial traffic to resume. But on Saturday, Iran issued a long list of demands that it said would have to be met before ships could move again through the strait, and it was clear that Iran wanted to continue to use the strait as leverage.

Oil prices rise.

• The price of Brent crude, the global benchmark for oil, notched up about 3 percent, to nearly $85 a barrel.

• West Texas Intermediate crude, the U.S. benchmark, was up around 2.5 percent, to almost $79 a barrel.

• Investors and analysts are focused on the continued disruption to shipping in the Strait of Hormuz, the narrow waterway between Iran and Oman that is a vital trading route for oil and natural gas that normally carries as much as one-fifth of the world’s oil supply.

Stocks slip.

• Futures on the S&P 500 pointed to less than a 1 percent decline when stocks resume trading in the United States on Monday.

Gasoline prices dip.

• Gas prices fell slightly on Sunday to a national average of $4.01 a gallon, according to the AAA motor club. While prices have dropped somewhat in the last week, drivers, on average, are still paying 34.6 percent more for gas than when the war began.

• Gas prices don’t move in lock step with crude, usually trailing increases or drops by a few days.

• The average price of diesel also fell slightly to $5.31 on Sunday, but costs are still up 41.2 percent since the start of the war.