As Wall Street remakes itself on a former rail yard in the far west of Midtown Manhattan, one surprising name is leading the way.

Wells Fargo & Co, the San Francisco-based lender known for its retail banking business, has picked out space for a trading operation to use as a base for a stealth attack on the investment banking world.

The bid for more capital markets business - from advising on deals and security issues to trading derivatives - is a potentially risky move by the third-largest U.S. bank by assets.

The boom-and-bust of Wall Street offers lucrative fees if Wells Fargo can pick up business left behind by rivals in the wake of the financial crisis of 2008, but trading brings extra risks and volatility.

Jonathan Weiss, who runs Wells Fargo's investment banking and trading division, said the bank's plans were deliberately low-key.

"We're not getting into things that are going to rapidly or dramatically change our business," he told Reuters in a phone interview earlier this month. "It's just a consistent, slow build-out. Add a person here, add a person there."

Despite Weiss's muted tone, Wells Fargo has made some headline-grabbing moves.

In December it announced a deal to buy 500,000 square feet - or 10 football fields - of trading and office space at Manhattan's Hudson Yards development. Its neighbors will include private equity firm KKR & Co and media titan Time Warner Inc.

Earlier this month it clinched what is expected to be its most lucrative mergers and acquisitions (M&A) assignment in at least a decade. And it has acquired a license to trade credit derivatives, so it can take advantage of revival in demand for a product starting to overcome its association with the last financial crisis.

Wells Fargo built itself into the world's most valuable bank - with a market value of $243 billion - in the wake of the financial crisis partly because it did not rely on risky trades or complex derivatives to turn a profit.