Stanley Fink, who oversaw a 10-fold increase in Man Group Plc’s assets under management during his seven years as chief executive officer, is finding it harder to keep investors at his latest hedge-fund firm.

Losses and client redemptions have reduced assets at International Standard Asset Management Ltd.’s main hedge fund by almost half over the past 18 months to $585 million, Fink, the firm’s CEO, said in an interview yesterday. London-based ISAM has responded by changing some of its management, examining why the fund hasn’t performed as well as expected and increasing the number of markets it invests in, he said.

“It’s a bit like when you lose a few races in Formula 1,” said Fink, 56. “You realize your car wasn’t as fast as you thought so you go back and re-engineer every part. The system is now very leading edge.”

The ISAM Systematic fund fell 14 percent in the nine months through September, after declining 17 percent in 2012 and 2.7 percent in 2011, hurt by a lack of the market trends that the firm relies on to make money, according to a letter sent to investors this month obtained by Bloomberg News. Since the end of 2010, the fund has declined 31 percent, more than three times the 9.7 percent fall in the Newedge CTA Index, which tracks the performance of hedge funds that use computer algorithms to profit from trends in asset prices.

Fink says the losses haven’t deterred him from a goal of building ISAM into a firm managing as much as $5 billion, which he set after taking the reins five years ago.

“The business is profitable,” he said. “We business- planned for drawdowns, which are, sadly, part of the business. In a period when performance is not good, there will not be significant bonuses. Staff are grown-up enough to know that.”

House of Lords

Fink, who sits in the U.K. House of Lords, is also the former co-treasurer of the country’s jointly ruling Conservatives and has contributed at least 3.7 million pounds ($6 million) to the political party since 2003, according to campaign finance disclosures. The U.K. Sunday Times estimates he has a personal fortune of 130 million pounds.

Fink joined ISAM in 2008 after stepping down a year earlier from Man Group, the world’s biggest publicly traded hedge-fund manager, which oversees $52 billion. In February 2010, he teamed up with Larry Hite, who had been running an earlier version of what became the ISAM Systematic fund out of his family office. Hite’s experience buying and selling assets based on signals from computer models goes back to 1981, when he started Mint Investment Management Co., according to ISAM’s website.

ISAM had about $200 million of money from outside clients when it started trading Hite’s investment system in May 2010.

Man Hires