NEW YORK (Bloomberg) - Allied World Assurance Company Holdings AG, the insurer whose co-founders include American International Group Inc. and Chubb Corp., repurchased a warrant from AIG for $53.6 million. Allied World rose to a four-and-a-half year high.The transaction was funded using cash on hand, Allied World said yesterday in a statement issued by PR Newswire. The warrant, the last one held by AIG, allowed it to purchase two million Allied World shares for $34.20 apiece.Allied World climbed 37 cents to $61.68 as of 12.55 pm in New York Stock Exchange composite trading, its highest level since July 12, 2006. It later pared some of those gains, closing up six cents at $61.51. It has climbed 35 percent in the past year.The insurer has been repurchasing securities from founding shareholders. In November, it agreed to buy 3.2 million shares and warrants to purchase 1.5 million shares from Goldman Sachs Group Inc. and other founding investors for $222.6 million. In August, the insurer bought back from Chubb a remaining warrant to purchase two million shares for $32.8 million.The repurchase transactions are separate from a $500 million share-repurchase programme approved in May 2010, Allied World said.Allied World was founded in Bermuda in 2001. It moved its holding company to Zug, Switzerland late last year, but still maintains insurance and reinsurance operations on the Island.