Bermuda insurer Ironshore has announced the appointment of another two experienced former American International Group executives to bolster its US operations.

Tim McAuliffe is to take over as president of Ironshore's US Specialty Casualty unit, while Ben Beauvais has been appointed senior vice-president of Specialty Casualty.

Mr. McAuliffe spent 14 years in leadership roles at AIG and was most recently president of AIG Excess Casualty. Mr. Beauvais spent 14 years at AIG's Lexington Insurance Company, where he was most recently head of the AI Risk Specialists unit.

Over the past six months, Ironshore has lured a string of executives from the US giant, including the Bermuda company's chief executive officer Kevin Kelley.

The appointments were a factor in the decision of credit rating agency AM Best Co. to remove Ironshore from being under review with negative implications and affirm the company's financial strength rating at A-.

Best said on Friday: "Ironshore has increased its employee count with experienced personnel to support the company's needs under its revised business plans.

"These seasoned veterans are familiar with Ironshore's new management team, having previously worked with most team members."

AIG has been badly hit by the exposure of its Financial Products unit to credit default swaps and has taken more than $150 billion in US government support to keep it afloat.

Other Bermuda companies have also attracted talent from AIG, including Hiscox, Validus and start-up Torus.

In statement on Thursday, Ironshore said Mr. McAuliffe would develop and manage Ironshore's US Specialty Casualty unit which will focus on underwriting in the primary specialty casualty, buffer casualty and lead umbrella/excess business.

Based in New York, he will reports to Shaun Kelly, CEO of Ironshore's US operations.

Mr. Beauvais, based in Boston, will work closely with Mr. McAuliffe as they build Ironshore's US Specialty Casualty unit.

At Lexington, Mr. Beauvais earned experience in general casualty, transportation, and energy casualty.

"We are excited to have both Tim and Ben join the Ironshore organisation," Shaun Kelly said. "Their diverse casualty underwriting background will be an asset to the Ironshore team as we expand our casualty product suite in the US."

The company added that its IronSelect unit will now become part of the Specialty Casualty unit.

AM Best had put Ironshore's ratings under review on February 3, because of the "material deviation from its original business plan and the execution risks of its new business model".

But on Friday, AM Best ended the review, affirming Ironshore's ratings with a stable outlook. The agency commented: "Since that time, Ironshore has successfully executed its new business initiatives despite very challenging market conditions.

"Some of the more notable of these include entering into strategic relationships to write catastrophe excess casualty and long-term environmental policies, securing pro-rata reinsurance in order to provide larger gross limits for clients and reducing the risk appetite for property catastrophe exposures."

AM Best added that it believed the deviation from the original business plan would be for the long-term benefit of Ironshore.

"The business profile of the group, a key component of the ratings process, has been enhanced by the diversification into lines of business not correlated with the company's property book of business," AM Best said.

"The outlook reflects A.M. Best's expectation that Ironshore's performance will benefit from a favourable rate environment in most targeted lines of business and capital will be managed prudently."