Lehman Brothers, Credit Suisse First Boston and Morgan Stanley Dean Witter have reaffirmed their positions as advisers to the world's big oil companies, with all three advising on the $45.4bn (€53bn) Texaco and Chevron merger.

Lehman is advising Chevron on the transaction, which could achieve annual savings of at least $1.2bn. The legal advisers to Chevron are Al Pepin, Fried Frank Harris Shriver & Jacobson and Pillsbury Madison & Sutro.