Royal Dutch Shell could make $1bn in the next two years by selling some of its North Sea assets, helping it pay for the BG takeover.
This could be achieved by streamlining Shell's Norwegian assets, according to a note released today by investment bank UBS.
"There is of course room to be even more radical, potentially exiting very significant pieces of business that have hitherto been regarded as core to the business," it said.
"These would be more difficult because the asset and relationships are more entrenched and there are bound to be more significant vested interests within the Shell organisation. But what better way would there be to signal a new, radically different business?"
Shell previously said it could sell some of its older, lower grade North Sea assets to help pay for its £35bn purchase of smaller rival BG. The company is targeting asset sales of $30bn over 2016-18.
Fund manager Neptune Oil has been touted as a potential buyer, while Danish oil and gas company Maersk could also be interested.