By Stephanie Kelly

(Reuters) - Oil prices edged lower on Tuesday, extending losses from the previous session, as investors worried about global oil demand following weak manufacturing data in several countries.

Brent crude futures fell 29 cents to $99.74 a barrel by 0002 GMT, with WTI crude futures down 22 cents at $93.67 a barrel.

The slide came after Brent futures slumped on Monday to a session low of $99.09 a barrel, their lowest since July 15. The U.S. crude benchmark dropped to as low as $92.42 a barrel, its weakest since July 14.

Prices have been volatile, as investors weigh tight global supply with fears of a potential global recession.

Recessionary concerns were heightened on Monday as surveys from the United States, Europe and Asia showed that factories struggled for momentum in July. Flagging global demand and China's strict COVID-19 restrictions slowed production.

The price drops also come as market participants await the outcome of a meeting on Wednesday between the Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia, together known as OPEC+, to decide on September output.

A Fox Business news reporter said Saudi Arabia will push OPEC+ to increase oil production at the meeting.

Two of eight OPEC+ sources in a Reuters survey said that a modest increase for September would be discussed at the Aug. 3 meeting. The rest said output is likely to be held steady.

Meanwhile the United States on Monday imposed sanctions on Chinese and other firms it said helped to sell tens of millions of dollars' in Iranian oil and petrochemical products to East Asia as it seeks to raise pressure on Tehran to curb its nuclear programme.

(Reporting by Stephanie Kelly; Editing by Kenneth Maxwell)