Billionaire hedge fund investor John Paulson has added to the pressure on Dow Chemical to close its acquisition of Rohm & Haas, in which Paulson’s funds are the second-largest shareholder and would therefore stand to gain if the controversial deal completes.

Paulson & Co. submitted a public letter today to Dow Chemical chief executive Andrew Liveris suggesting ways to finance the deal after Dow failed to complete the $15bn (€11.7bn) deal by its deadline of this past Tuesday, prompting a lawsuit from Rohm & Haas.