Be careful on this emerging markets play: Pro

Jankara market, located on Lagos Island and the skyline of Lagos, Nigeria.
Derrick Ceyrac | AFP | Getty Images

Optimism on investing in Africa needs to be tempered—even if there's plenty of opportunity, according to a top money manager at AllianceBernstein.

"I am hopeful ... that we will see very strong growth in Africa over the coming decades and that that will translate into very strong economic returns for investors," Morgan Harting, a senior portfolio manager focused on emerging markets at AllianceBernstein, said Wednesday at the FT Frontier Markets Summit in New York. "But I don't think either is a given, and I'm not sure investors are pricing that uncertainty today appropriately."

The key to investing in Africa is picking the right companies, Harting said. He noted a "mania" about the rise of the middle-class consumer leading some African stocks to be valued at 40 times earnings despite growing no faster than a European consumer company that trades at much lower multiples.

"We have significant investments in Africa. We're optimistic. But we don't just buy 'Africa.' You can't. You have to be discerning," he said.