Jefferies, the US bank that has more than doubled its advisory revenues this year on the back of an unrelenting period of expansion, has been picked to work on a multi-billion dollar deal in the US energy sector.

Chevron, the US oil company, said in a statement yesterday that it had agreed to acquire Atlas Energy for $3.2bn in cash and $1.1bn of assumed debt in order to access natural gas reserves in Pennsylvania's Marcellus Shale.