Oil futures rose more than 5% in late trading Tuesday afternoon as the close of the market approached, reversing steep losses seen in recent days.

The buying was driven by a rise in the equity markets on optimism for a substantive resolution to ongoing euro-zone debt woes, and analysts said at least some of the activity came from short-sellers covering bets taken against the market in recent days, when sentiment had been negative on a host of economic worries.

Light, sweet crude for November delivery was up $4.25, or 5.3% at its highest intraday point, to $84.49 a barrel on the New York Mercantile Exchange. Brent crude on the ICE Futures Europe exchange was up $2.78, or 2.7%, to $106.72 a barrel.

If the gain holds, it will be the largest rise in crude prices since May 9.