Nov 28 (Reuters)—Reinsurer Validus Holdings on Monday withdrewits offer for peer Transatlantic Holdings, ending a months-longhostile takeover battle.

Validus, which has a history of hostile bids for otherreinsurers, launched its offer in July, attempting to break up adeal Transatlantic already had with Allied World Assurance CoHoldings Ltd .

While it succeeded in that effort—Transatlantic and Alliedcalled off their deal in September—Validus was ultimately unable towoo Transatlantic's management or its shareholders.

In a filing with the U.S. Securities and Exchange Commission,Validus said it would return about 7.7 million Transatlanticshares, representing a 13.4 percent stake in the company, tenderedin the offer to the shareholders.

In the filing, Validus said certain condition to its tenderoffer, which expired on Nov. 25, were not satisfied. The filing didnot say what Validus intended to do about its lawsuits againstTransatlantic or its consent solicitation to replace the company'sboard.

Last week, Transatlantic's board, which had repeatedly rebuffedValidus, accepted a $3.4 billion stock and cash deal from propertyand casualty insurer Alleghany Corp .

While the Validus offer was actually worth more than theAlleghany bid on paper, the breakup fee in the Alleghany deal allbut wiped out Validus's financial advantage.

Had Validus succeeded, it would have been the second time in twoyears it won a hostile bid for a peer, after snapping up reinsurerIPC in 2009.

Validus shares rose 2.1 percent to $29.40 in early trade. Priorto Monday's open, the stock had been down 6.6 percent frommid-July, when it first bid for Transatlantic.

At one time following the bid the stock had lost as much as aquarter of its value, but it has rebounded steadily since lateSeptember.