Coca Cola posted better-than-expected profits on Tuesday after a surprise rise in sales in North America, its biggest market.

Coke's sales in North America had flatlined or even slumped over the previous three quarters, with consumers dropping the soft drink for healthier options, so the final quarter sales rise has surprised analysts.

North American sales increased 2% in Q4, reaching $5.37bn (£3.52bn), which accounts for around half of overall sales.

Analysts have argued that US consumers are actually paying more for Coke, rather than drinking more of the beverage. The soft-drink's price rose 4% in Q4.

A number of broader economic factors likely helped American sales, with low oil prices and an ever-strengthening jobs market encouraging consumers to part with their dollars.

Oil prices fell dramatically in the second half of 2014, having a knock-on effect on the price consumers were paying at the pump for gasoline in North America.

Coke said at the end of 2014 that it would reduce its workforce by 1,600 to 1,800 positions as part of a plan to reduce costs by $3bn by the end of 2019.