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May 7 (Reuters) - Canadian Natural Resources CNQ.TO, the country's largest oil and gas producer, exceeded first-quarter profit expectations on Thursday, fueled by higher production in its oil sands segment as well as conventional operations.

Canada's oil sands producers continue to benefit from operational efficiency gains and stable output despite persistent concerns around pipeline constraints and volatile commodity prices.

Its output grew to 1.64 million barrels of oil equivalent per day in the three months ended March 31, from 1.58 million boepd a year earlier, Canadian Natural said.

It benefited from its Jackfish thermal oil sands project, where production averaged a record 134,396 barrels per day, exceeding its maximum output capacity.

It also reported record quarterly North American natural gas production of 2.67 billion cubic feet per day.

The Calgary, Alberta-based company said April output from its oil sands assets rose to about 630,000 barrels per day, with facilities running above full capacity.

Realized prices for natural gas rose 5.7% to C$3.32 per thousand cubic feet, while total realized prices for exploration and production liquids fell 4.8% to C$76.02 per barrel.

Peers Cenovus CVE.TO Energy reported strong quarterly earnings, driven by record upstream production.

Canadian Natural reported adjusted profit of C$1.17 ($0.8587) per share for the three months ended March 31. Analysts on average had expected profit of C$1.01 per share, according to data compiled by LSEG.

($1 = 1.3626 Canadian dollars)