* Plans to nominate three new directors
* Three advisory firms now recommend against Allied deal
* Shareholders set to vote on Allied offer Sept. 20
Sept 14 (Reuters) - Reinsurer Validus Holdings (VR.N) increased the pressure on its target Transatlantic Holdings TRH.N on Wednesday, filing paperwork with regulators to ultimately replace Transatlantic's board of directors.
Transatlantic shareholders are due to vote next Tuesday on an all-stock offer from Allied World (AWH.N), which three proxy advisory firms have recommended they reject. Transatlantic's largest shareholder also opposes the deal, and an Allied executive said this week the deal was unlikely to succeed.
Against that backdrop, Validus said Wednesday it had filed a preliminary consent solicitation with the U.S. Securities and Exchange Commission, seeking written permission from Transatlantic investors to remove and replace the board.
The three proposed new directors are Raymond Groth, a professor at the Fuqua School of Business at Duke University and retired investment banker; former Canadian pension executive Paul Haggis; and financial services industry consultant Thomas Wajnert.
The battle for Transatlantic has been highly contentious, with multiple lawsuits and accusations of misbehavior on all sides. Transatlantic and Allied agreed to a deal in June, and Validus stepped in with its offer a month later.
New York-based Transatlantic, which was controlled by AIG until 2009, has a concentration in "long-tail" lines of insurance, like medical malpractice and workers compensation, where claims can take years to develop. That has been seen as an attractive addition for reinsurers that are more heavily exposed to "short-tail" risk like natural disasters.
Validus shares rose 0.6 percent and Transatlantic's shares rose 0.1 percent in early trading, while Allied shares were flat. At current levels, Allied's bid is worth $2.92 billion and Validus' is worth $2.97 billion.
Meanwhile, little is known about the state of Transatlantic's talks with Berkshire Hathaway (BRKa.N), which made an unsolicited all-cash bid as well. That offer is worth $3.25 billion, and the two sides have been negotiating after signing a confidentiality agreement. (Reporting by Ben Berkowitz, editing by Maureen Bavdek)