Greener grass money manager Isaac Green expands amid difficult times for Durham's 'black wall street.'.

• Author: Barnes, Clifton, III
• Position: MONEYTALK: North Carolina's financial set

While Durham's better-known African-American financial pillars teeter, Isaac Green's less publicized Piedmont Investment Advisors LLC is thriving. Green, an heir to the families that established Durham as a national leader in black-owned financial services in the late 19th century, heads one of North Carolina's largest money managers. It has more than doubled in size over the last two years to about $6 billion after securing a key deal with North Carolina's state pension fund.

In September, Piedmont acquired Durham-based NCM Capital Management, founded in 1986 by Maceo Sloan, who became nationally known during frequent appearances on the public-TV show Wall Street Week with Louis Rukeyser. At its peak, NCM managed $3 billion, but disappointing performance and staff infighting caused assets to decline to $470 million at the time of the sale. Sloan has no day-to-day role, though he advises Piedmont.

Other historic Durham companies also are struggling amid mounting industry regulations and consolidation. N.C. Mutual Insurance Co. and M&F Bancorp face serious challenges. N.C. Mutual, formed in 1898 and the largest U.S. black-owned insurer, was downgraded to "marginal" from "fair" by the A.M. Best rating agency in May after its capital declined to less than $10 million.

M&F Bank (formerly Mechanics and Farmers Bank), the second oldest minority-owned bank in the U.S., laid off 11% of its staff, delisted its stock and reported a loss of $148,000 in the first half of 2016.

Piedmont shows a different trajectory. In August, Piedmont repurchased a 30% interest that Conshohocken, Pa.-based private-equity group Rosemont Investment Partners LLC bought in 2011. As a result, Piedmont is now 100% owned by current and former employees, including founders Green, Executive Vice President Sumali Sanyal and Dawn Alston Paige, who no longer works at the company. Started in 2000, it employs 25 with an average tenure with the company of about 10 years.

Much of Piedmont's growth stems from clients who started by investing $10 million or less but now have placed $400 million to $500 million, Green says. "This speaks to their trust in the Piedmont investment process."

In its most recent firm publication, Piedmont says it has advanced its identity "as a minority- and women-owned business, and [we] believe our stability and strength is a great...