Calgary, Alberta-based Encana, which produces gas and light oil, has benefited from whittling down its operations to focus on its four core North American assets: acreage in Montney and Duvernay in Western Canada and assets in the prolific Eagle Ford and Permian shale fields in Texas.

Production from core assets jumped 32 percent to 313,200 barrels of oil equivalent per day (boe/d).

The company said on Thursday total quarterly production increased to 335,200 boe/d, from 321,500 boe/d a year earlier. It realized $52.94 per barrel of oil production, compared with $50.78 a year ago.

The company also announced a buyback of up to $400 million worth in shares.

"We have further demonstrated our confidence in our five-year plan and our commitment to shareholder returns with the announcement of our share repurchase program which we plan to fund with cash on hand," Chief Executive Officer Doug Suttles said in a statement.

The company's net loss narrowed to $229 million - and reflected a non-cash deferred tax charge primarily due to a fall in tax rates in 2017 related to the U.S. tax reform - from $281 million, a year earlier.

Encana expects to spend between $1.8 billion and $1.9 billion in 2018, up from $1.6 billion to $1.8 billion it had forecast for 2017.

Last month the company said it plans to invest nearly 70 percent of this budget to boost production in Permian and Montney, as oil investors pressure producers to improve production without significantly increasing capital budgets.

Encana said it expects production for 2018 to be between 360,000 boe/d and 380,000 boe/d. Total production in 2017 was 313,200 boe/d.

Excluding one-time items, the company earned 12 cents per share in the fourth quarter, above analysts' average estimate of 10 cents per share, according to Thomson Reuters I/B/E/S.

(Reporting by Anirban Paul in Bengaluru; Editing by Shailesh Kuber and Sayantani Ghosh)

By Anirban Paul