US supermajors ExxonMobil and Chevron both saw narrower profits in the first quarter after being hit by lower downstream margins, but strong liquids output and a robust project pipeline offered reasons for optimism.

ExxonMobil's net profit for the three months to March was $2.4 billion, well down on the $4.7 billion seen in the comparable period a year earlier. Revenues fell to $63.63