(Reuters) - HSBC's ( HSBC ) latest oil market supply and demand model envisions OPEC+ gradually unwinding 1.65 million barrels per day in "first-phase" voluntary production cuts over a 12-month period, the bank said in a note on Tuesday.

The bank's oil market model had previously assumed that OPEC+ would take a breather after unwinding 2.2 million barrels per day (bpd) of cuts, and wait until 2026 to add more barrels.

"However, the group seems undeterred by negative demand seasonality and the prospect of a market surplus," HSBC ( HSBC ) said in the note.

At its meeting this month, OPEC+ opted to further increase oil production by 137,000 bpd in October, starting to unwind the 1.65 million bpd in cuts ahead of schedule.

Although the group has been increasing production since April, its decision came as a surprise amid expectations of a supply glut in the northern hemisphere going into winter.

The move increases the downside risks for oil prices, analysts at Commerzbank said in a note, prompting them to trim their Brent price forecast for the coming year to $65 per barrel, down from $70.

They said that was due to expectations of oversupply, despite supply risks from continued Ukrainian drone attacks on Russian energy infrastructure, and the potential for U.S. tightening sanctions against Russia and buyers of Russian oil.

Brent crude was up 0.71%, to $66.49 a barrel by 1011 GMT, while U.S. West Texas Intermediate crude rose 0.79% to $62.75 a barrel. [O/R]