A sign for BlackRock Inc hangs above their building in New York U.S., July 16, 2018. REUTERS/Lucas Jackson

NEW YORK (Reuters) - BlackRock Inc BLK.N is giving the executive behind the company's key iShares brand a job overseeing strategy, marketing and international businesses as the world's largest asset manager grooms possible successors to Chief Executive Larry Fink. Mark Wiedman, who has led the company's fast-growing index investing unit, will take the title head of international and of corporate strategy, Fink said in a memo seen by Reuters on Wednesday. Wiedman will be reporting to Fink, one of BlackRock's founders in 1988.

Fink has neither signaled any intention to leave nor publicly named a successor, but Wiedman is among a small group tipped as possibilities, including President Rob Kapito, Chief Operating Officer Rob Goldstein, Head of the Americas Mark McCombe, and Richard Kushel, the head of multi-asset strategies and global fixed income.

“The changes transforming our industry put a premium on strategy to drive growth, on unifying our focus on international markets, and on using our brand to drive our business,” Fink said in a memo announcing staffing changes. “With these changes, and others we’ll make later this year, our aim is to bring the firm closer together, to simplify our organization, to make us more nimble, and to create new opportunities to drive growth and serve our clients.”

In 2018, investors sold off asset managers’ stocks as wild-swinging markets cut funds’ returns, accelerating a stampede to lower-fee products.

BlackRock’s iShares unit has a leading position in exchange-traded funds (ETFs), which typically track the market and are cheaper than products that try to beat the market. And while BlackRock has often been able to defend its pricing in iShares, investors fear a race to zero in that business, too.

BlackRock’s stock is down nearly a third from an all-time high near $600 per share last year. It traded around $400 on Wednesday.

A former senior adviser at the U.S. Treasury and McKinsey & Co management consultant, Wiedman came to BlackRock in 2004 to run a unit focused on advising other financial institutions and governments. He took on responsibility for iShares, which BlackRock bought from Barclays plc BARC.L during the global financial crisis, in 2011.

In his memo, Fink said Salim Ramji, an executive who runs a unit involved in selling the company’s funds through financial advisers and brokerages, will oversee the company’s ETF and Index Investments business and report to Kapito. Martin Small, who runs iShares in U.S. and Canada, is succeeding Ramji and reports to McCombe.