SINGAPORE - Brent crude oil fell on Monday as investors prepared for an extra 1 million barrels per day (bpd) in output to hit the markets after OPEC and its partners agreed to raise production.

Despite the increase, which is intended to stop the gap between global supply and demand from becoming too wide, analysts said global oil markets would likely remain relatively tight this year.

Brent crude futuresfell $1.15 to $74.40 a barrel by 1448 GMT, while U.S. light crude  rose 20 cents to $68.78 a barrel, supported in part by a Canadian supply outage. 

Prices initially jumped after an OPEC deal to increase output was announced late last week, as it was not seen boosting supply by as much as some had expected. 

OPEC and non-OPEC partners including Russia have since 2017 cut output by 1.8 million bpd to tighten the market and prop up prices.

"OPEC are really going all-out to prevent oil prices from biting in the second half of the year," SEB head of commodities Bjarne Schieldrop said.

"It was a very strong message - we are going to meet demand and we're not going to disappoint consumers."

After officially meeting on Friday, OPEC gave a press conference on Saturday that implied a bigger increase in supply.

"Saturday's OPEC+ press conference provided more clarity on the decision to increase production, with guidance for a full 1 million bpd ramp-up in 2H18," Goldman Sachs said in a note on Sunday.

"This is a larger increase than presented Friday although the goal remains to stabilize inventories, not generate a surplus," the U.S. bank added. 0Q

Largely because of unplanned disruptions in places such as Venezuela and Angola, the group's output has been below the targeted cuts, which it now says will be reversed by supply increases, especially from OPEC leader Saudi Arabia. Analysts warn however there is little spare capacity for large-scale output increases. 

"As yet there is no plan as to how the limits will be reallocated. One simple approach would be to reduce the limits of those not producing enough by 600,000 bpd and increase the limits of members with spare capacity by 600,000 bpd – this would enable 100 percent compliance," said Callum MacPherson, Investec head of commodities.

Goldman Sachs also warned that an "outage at Syncrude Canada's oil sands facility could leave North America short of 360,000 bpd of supply for all of July". 

It added that this "will exacerbate the current global deficit, making the increase in OPEC production all the more required".

The premium of Brent crude over U.S. futures narrowed to around $5.21 a barrel on Monday, down from nearly $10 a week ago, thanks to the steep drop in the premium of U.S. coastal grades over the West Texas Intermediate benchmark price.

Additional reporting by Henning Gloystein in SINGAPORE; Editing by Jan Harvey/David Evans) ((; +442075423424; Reuters Messaging:; Twitter: