Meanwhile, Kelly says his continued role as chairman will not include stepping on Long's toes. “My involvement will be defined by his desires,” Kelly says to NU. “He's running the company.”

Kelly has been CEO since 1998. He began with the company in 1992 as president and COO.

Long was named president about a year ago.

To anyone who may think that Liberty Mutual will sit on its hands once Long takes over, the new top executive says, “That isn't going to happen.”

Long calls mergers and acquisitions a “core competency around here,” and says the company's ever-present desire to seek out the next opportunity in the United States and abroad “isn't going to stop.”

He adds, “I like the path we're on.”

Liberty Mutual's plan to tap the middle class in emerging markets isn't going to stop either, he adds.

“If you can afford to buy a car, we want to be there to insure it,” Long says.

Internationally, Liberty Mutual is looking at Russia, Indonesia and is “nibbling” at Africa for growth opportunities, Long says. The company is also looking at the effect new solvency rules have on companies overseas. It may be that the new rules overburden some companies, allowing Liberty Mutual to step in and help with capitalization, as it recently did in Ireland.

Under Kelly's leadership, Liberty Mutual embarked on a plan to spread its global footprint, expanding to places like Latin America, Ireland and China.

Globalization was an “inexorable trend,” Kelly says. “We had a choice to go global or try to remain a successful regional insurer.” There were doubters, but Kelly says there were likely doubters when Liberty Mutual decided to go into New Jersey, for instance.

The landscape of companies that decided to remain steadfast regionals is scattered with failure, he says. “Lots are gone,” adds Kelly, who has warned that North America-only companies will eventually become irrelevant.

Both Kelly and Long spoke of the advantages of the company's status as a mutual. Kelly says being a mutual allowed the company to “take a longer-term view” of some moves that he admits would have been difficult to convince investors to get behind.

Long says being a mutual allows the company to be “slightly more patient, compared to the competition.” Therefore, he notes, it can acquire distressed companies in Ireland or Venezuela, or get into markets as it has in places like China, Vietnam and Poland.

The acquisition of Safeco—one of Kelly's biggest accomplishments—is now showing growth. The move was a “home run,” Long says. “Their book of business is more profitable than we thought.”

A look at Liberty Mutual since Kelly was appointed CEO reveals tremendous growth. Total assets at the end of 1998 were $26.25 billion. At the end of 2010 they stood at $63.14 billion. Net premiums written after 1998 were $6.52 billion compared to $21.48 billion at the end of 2010. Policyholder surplus grew to more than $16 billion at year-end 2010 from just more than $7 billion in 1998.

Yet Kelly believes Liberty Mutual's employees had much more to do with the company's success.

“We made sure the rank and file participated in the success. They deserve it,” says Kelly, who adds that hundreds of millions of dollars in bonuses have been doled out to non-management employees.

Travel and family time are included in the soon-to-be-retired executive's plans. So is music, he says. Kelly is to become the chair of the Boston Symphony Orchestra board.

“It's something I'm really excited about,” he says.

Asked if there was anything he wishes he could have done during his time as CEO, Kelly shares a story of childhood in Ireland.

“We'd climb the hills and we'd get to the top, tired,” he says. “Then there was another ridge. There's always another ridge. No, I have no regrets.”