The new chief executive of Anglo-Dutch oil and petrochemicals giant Shell, Ben Van Beurden, has announced a "fix or divest" strategy to improve earnings.

Plans include reduction of the budget for onshore gas extraction in the Americas - including the U.S., Canada and Argentina - as well as divestment of assets worth $15 billion, or 3% of the portfolio, by the end of 2015.

In the recent past, Shell has divested assets worth $4.5 billion, pulling out of at least two downstream projects in Australia and agreeing the sale of its retail and aviation businesses to Kuwait Petroleum.

In another pullback that will relieve environmental protection groups in the U.S., the group has shelved plans to drill off the coast of Alaska.

The moves come amid a poor performance of Shell's shale gas operations in North America. In particular, a sobering analysis of its wells in the Marcellus Basin in the U.S. state of Pennsylvania in the second half of 2013 revealed that the "vast majority" of its 630 wells performed less profitably than those of rivals.

"From 2014, tight-gas and liquids-rich shale will have a different role in our strategy," Van Beurden said, while stressing that this is a longer-term perspective. At the same time, he said the group is "reducing the number of these opportunities in our North American portfolio as we strive to improve our financial performance."

In a presentation concurrent with the publication of Shell's annual report, the new CEO said the $80 billion in capital they employed in North America is not producing the desired returns. In fact, returns across many of its global businesses have been deficient.

In January of this year, the group based in The Hague issued a profit warning for last year's fourth quarter, which saw profits down 48% - the worst performance for five consecutive quarters. Impairment charges of almost $2.5 billion, for the most part related to writedowns - some of which are not tax-deductible - were taken on the value of the US shale gas and tight oil business.

Former chief executive Peter Voser resigned at the end of December.

Shell's refinery business also has seen stress cracks, reflecting overcapacity in the oil sector and weakening demand, and the group said the lubricants business also has underperformed. Here, too, management has hinted at divestments.