NEW YORK (REUTERS) - Goldman Sachs Group Chief Executive Lloyd Blankfein became the first major Wall Street leader to speak out against President Donald Trump's order to halt arrivals from several Muslim-majority countries.

In a voicemail to employees on Sunday (Jan 29), Mr Blankfein said diversity was a hallmark of Goldman's success, and if the temporary freeze became permanent, it could create "disruption" for the bank and its staff.

"This is not a policy we support, and I would note that it has already been challenged in federal court, and some of the order has been enjoined at least temporarily," Mr Blankfein said, according to a transcript seen by Reuters.

In Silicon Valley, the heads of companies such as Apple and Facebook swiftly denounced Mr Trump's immigration ban. But the rest of corporate America has been more circumspect in speaking out, underscoring the sensitivities around opposing policies that could provoke a backlash from the White House.

Tepid responses from many of Mr Blankfein's peers made his comments all the more potent, especially because Goldman has gotten attention for the number of its alumni who have joined Trump's administration.

Top BlackRock executives including CEO Larry Fink sent a memo to staff on Monday saying Mr Trump's order presented "challenges" to its goals of diversity and inclusion. BlackRock is examining the direct impact on its employees, as well as the broader implications of the order, they said.

"We, of course, all want to promote security and combat terrorism, but we believe it needs to be done with respect for due process, individual rights and the principle of inclusion," they wrote.

Citigroup CEO Mike Corbat said in a memo to employees on Monday that the bank is concerned about "the message the executive order sends" as well as the impact immigration policies might have "on our ability to serve our clients and contribute to growth".

JPMorgan Chase & Co's operating committee, which includes CEO Jamie Dimon, avoided directly criticising the policy. In a note to staff over the weekend, the firm said it was reaching out to all employees affected and noted that the country was "strengthened by the rich diversity of the world around us".

Bank of America Corp CEO Brian Moynihan wrote in an internal memo obtained by Reuters and confirmed by a spokesman that the bank is "closely monitoring" the order and connecting with staff who may be affected and have questions. "We depend upon the diverse sources of talent that our teammates represent," the memo stated.

Other banks, including Morgan Stanley and Wells Fargo & Co, said they were reviewing the executive order and its implication on staff.

Representatives for stock exchange operators Bats Global Markets, Nasdaq Inc and New York Stock Exchange parent Intercontinental Exchange all declined to comment.

The US hedge fund industry was also virtually silent on the immigration restrictions. Representatives for most major firms - including Bridgewater Associates, Renaissance Technologies, Millennium Management and Two Sigma Investments - did not respond to requests for comment over the weekend.

Private equity firms, including Blackstone Group LP, whose CEO, Stephen Schwarzman, chairs Mr Trump's advisory panel of business leaders, also would not comment on the travel ban.

People familiar with some of the banks' and firms' decisions in making public statements said a fear of riling Mr Trump was inhibiting most CEOs' responses.

Since the election, he has taken to Twitter to excoriate certain companies, causing stock price swings. And because Wall Street is hoping for an easing of financial reform regulations, most firms want to stay in Trump's good graces, they said.

The most high-ranking Goldman executive to have joined the Trump administration is former Chief Operating Officer Gary Cohn, who left the bank in December to become head of the White House National Economic Council. Others include Treasury Secretary nominee Steven Mnuchin and Trump advisers Steve Bannon, Anthony Scaramucci and Dina Powell.

Those recruits have put the Goldman back in the spotlight as a bank that long had influence in government and public policy, from the days of the Great Depression to the 2008 financial crisis.

But after the bank was embroiled in scandals over its mortgage-market bets, it embarked on a campaign to improve its image. Blankfein has promoted its focus on philanthropy and diversity initiatives, as well as Goldman's role in job creation.