Investment banks Perella Weinberg and Tudor, Pickering, Holt and Co are understood to be in talks over a possible merger.
New York-based Perella, which recently advised Deutsche Boerse on its proposed merger with the London Stock Exchange, is the bigger of the two banks. Tudor, Pickering, Holt and Co is an energy-focused boutique bank based in Houston, Texas.
The talks between the investment banks are ongoing and could result in a merger, partnership or no deal, a person briefed on the matter told Reuters.
Perella and Tudor, Pickering, Holt and Co have been asked for comment.
Read more: Citigroup profits plunge 27 per cent
News of the possible deal has emerged at the beginning of a tough year for investment banking, with mergers and acquisitions (M&A) activity down significantly on a record 2015.
Figures from both Dealogic and Thomson Reuters suggested investment banking revenue dropped to a post-crisis low in the first quarter of 2016.
According to Thomson Reuters, global fees reached $16.2bn (£11.4bn) by the end of the March this year, making it the lowest first quarter since 2009, and down 29 per cent year on year.