Jim McCaughan, a Scottish-born mathematician with an elite education and top-drawer experience, is hoping to secure the reputation of Principal Financial Group Inc.’s money management arm at the top of the industry.

His responsibility is large. Principal Global Investors manages about $90 billion in assets, the bulk of the total amount of money under the control of Principal Financial, the nation’s largest manager of 401(k) retirement accounts.

To put that figure into perspective, Principal Global could buy General Motors Corp., Ford Motor Co. and DaimlerChrysler AG, and still have enough money left over to snap up every publicly traded company in Central Iowa.

McCaughan’s chief goal, and his biggest challenge, is to boost the division’s investment returns. The better his team performs, the more clients Principal Global will win and the more customers that will be attracted to the products Principal Financial offers. Should returns suffer, customers may search for other money managers to handle their accounts.

“We’re playing in the big leagues here,” he said. “The more we provide good investment management, the more this whole organization benefits.”

To do that, McCaughan, who succeeded Dennis Francis as chief executive of Principal Global in December, is leading an effort to speed communication among the unit’s 350 analysts and give them more powerful tools to research stocks, bonds and real estate investments worldwide.

McCaughan, a former president of Oppenheimer Capital, is also making a bet on the growing strength of the underdeveloped world by either opening offices or adding workers in Brazil, Chile, Mexico, Hong Kong, Malaysia and India. Principal Global has roughly 800 employees in offices around the world.

Principal Global, which changed its name in October from Principal Capital Management LLC, has a growing track record of successes. It is now, in many ways, close to being considered a top tier firm.

The value of the assets Principal Global manages rose by 7.7 percent in 2002, a year when major stock indexes around the world plummeted. Principal Global was able to increase its assets both because of its investing acumen and because Principal Financial continues to add to its client list.

That performance is a large part of the reason Barron’s recently ranked Principal’s mutual fund products among the 10 best in the United States, alongside marquee names such as the Harris Investment Management and Franklin Templeton families of funds.

In February, Des Moines-based Meredith Corp., the publisher of Better Homes & Gardens magazine and the owner of 11 television stations across the country, said it had chosen Principal to manage its 401(k) retirement plan, which has about $140 million in assets. Meredith Chairman and Chief Executive William Kerr is also a member of Principal’s board of directors.

Principal Global doesn’t just invest money for its corporate parent. Last year, the company won $5.8 billion in new business from 28 institutional clients. The company manages about $16 billion in assets for clients outside of Principal Financial.

Principal Global manages close to $20 billion for insurance companies, $18 billion of which belong to Principal Life Insurance Co. It also manages $56 billion for Principal’s Retirement and Investor Services, which includes Principal’s mutual fund products, as well as other retirement plans administered by Principal Financial.

Recent new accounts include the California State Teachers’ Retirement System, the International Association of Machinists and Aerospace Workers District No. 9 pension fund, as well as public pension plans for the states of Michigan and Washington. Principal Global manages money for five of the nation’s 25 largest pension funds.

“We want to be one of the best, if not the biggest,” McCaughan said.

The company recently began using new software that lets its analysts use a common standard to produce research on foreign and domestic companies. Having that common platform will speed research and make it easier to make decisions on investing in companies that are located overseas.

Principal Global works to find investments in three main areas: equities, bonds and real estate. The company’s equity department manages about $15 billion. Its real estate portfolio is valued at slightly more than $20 billion. Its fixed-income business manages more than $50 billion in assets.

McCaughan, one of just five executive vice presidents who report directly to Principal Chairman and Chief Executive Barry Griswell, has spent the bulk of his professional career in London. He earned bachelor’s and master’s degrees in mathematics at the University of Cambridge’s Pembroke College.

He began working as an actuary in London in 1974 with Lane & Peacock. From there, he moved to Phillips & Drew, which was later acquired by UBS AG and folded into UBS Asset Management. At UBS, McCaughan moved to Zurich and later to New York, where he served as chief executive for institutional asset management in North America. Previous positions at UBS included head of international business.

In New York, McCaughan moved to Oppenheimer Capital, where he was president and chief operating officer. Most recently, he was chief executive for the Americas for Credit Suisse Asset Management, now part of Credit Suisse First Boston.

As a manager, McCaughan views his role as that of coach. He came to Des Moines partly out of curiosity about the Midwest. Mostly he came for the chance to work at a senior level for a Fortune 500 company that “has a clarity of purpose,” a reference to the conflict-of-interest troubles that are roiling some money management and investment banking firms on Wall Street, including Credit Suisse, his former employer.

“This was a chance to run an asset management firm that has a very collegial culture,” he said. “Also important to me was the chance to be an executive vice president of such a strong team. I am very appreciative of that.”