UPDATE 1-Shell profits halve on weak oil, gas prices

Ron Bousso and Shadia Nasralla

* Q4 profit falls to $2.9 bln

* 2019 profit down 23%

* Plan to complete $25 bln buyback "unchanged" -CEO (Adds detail)

LONDON, Jan 30 (Reuters) - Royal Dutch Shell's fourth-quarter profit halved to $2.9 billion, its lowest in more than three years, on weaker oil and gas prices as the company took a $1.6 billion charge on its U.S. gas fields.

The Anglo-Dutch energy company warned again that slowing global economy could affect the pace of its $25 billion share buyback programme, but CEO Ben van Beurden said Shell still intended to complete it.

"Our intention to complete the $25 billion share buyback programme is unchanged, but the pace remains subject to macro conditions and further debt reduction," van Beurden said.

Shell took a $1.65 billion charge in the fourth quarter mainly due to impairments on its onshore natural gas fields in North America. Rivals including Chevron and BP have also taken a number of large impairments in recent months.

The 48% drop in net income attributable to shareholders, based on a current cost of supplies (CCS) and excluding identified items, contrasted with a profit forecast of $3.2 billion, a company-provided survey of analysts showed.

Shell's third quarter profits were $4.8 billion.

For 2019, Shell's profit was $16.5 billion, down 23%.

Although rising tensions in the Middle East and a Phase 1 trade deal between the world's top two economies boosted oil prices to above $70 a barrel in early January, prices fell below $60 this week as China's outbreak of coronavirus exacerbated fears of a global economic slowdown.

(Reporting by Ron Bousso and Shadia Nasralla; editing by Jason Neely)