NEW YORK (Reuters) - Goldman Sachs Group Inc will detail plans to turn around performance at its core bond-trading unit next month after unusual pressure from large investors frustrated by vague explanations of its troubles, people familiar with the matter told Reuters.

A Goldman Sachs sign is displayed inside the company's post on the floor of the New York Stock Exchange (NYSE) in New York, U.S., April 18, 2017. REUTERS/Brendan McDermid

The move is a break from tradition at Wall Street’s pre-eminent bank, which usually gives its investors little information about how it makes money.

That was the case last month, when Goldman reported a stunning 40-percent decline in bond-trading revenue, much worse than rivals like Morgan Stanley and JPMorgan Chase & Co.

Goldman Chief Financial Officer Marty Chavez said Goldman had trouble “navigating” the markets during a conference call to discuss second-quarter results on July 18, but did not offer specifics.

That, and his vagueness over the causes of Goldman’s problems, unsettled some investors.

“You were left with reading about what ‘navigating the market,’ means and that doesn’t feel satisfying,” said Ian McDonald, a U.S. bank analyst at Janus Henderson, which owns 2.5 million Goldman shares.

“Did they cut too deep on the bench? Are they not in a position to be taking on risk as much as peers?” he asked.

McDonald said he has faith in Goldman’s trading prowess and its stock, but wants the bank to do a better job of communicating its strategy.

Goldman Sachs spokeswoman Ida Hoghooghi declined to comment.

INVESTOR FRUSTRATION

The level of investor frustration is testing Goldman’s time-tested “black-box” strategy of disclosing little and letting results speak for themselves. The bank does not offer targets or forecasts, and its quarterly disclosures are much sparser than those of its peers.

President and Co-Chief Operating Officer Harvey Schwartz will break that tradition at an industry conference on Sept. 12, the people familiar with the matter told Reuters, and explain what management is doing to turn the bond-trading business around.

That comes after two months of attempts by Goldman to patch up relations with investors. Executives including securities group co-head Pablo Salame have been meeting privately with investors and analysts to assuage concerns, the sources said.

The executives have explained how Goldman is trying to get investment bankers and traders to generate more revenue by working more closely together, sources familiar with the conversations said.

That attempt to soothe relations has not produced results. Seven investors who oversee a total of $3.3 billion in Goldman shares have told Reuters they are unsatisfied with management’s response so far.

The appearance of Schwartz in September may help turn the tide. A former co-head of securities and Chavez’s predecessor, Schwartz has developed a reputation for explaining Goldman’s approach to complicated issues, like capital rules, in a way that investors understand and appreciate.

In contrast Chavez - who took on his role in April - answered a long-running question about the viability of Goldman’s bond trading operation by saying: “It could be secular, it could be cyclical, doesn’t matter, who knows?”

The words of the CFO have extra weight at Goldman as CEO Lloyd Blankfein does not participate in quarterly earnings calls.