According to the Journal report, the U.S. Securities and Exchange Commission sent the letters to Goldman Sachs Group Inc (>> Goldman Sachs Group Inc), Morgan Stanley (>> Morgan Stanley), Citigroup Inc (>> Citigroup Inc), Credit Suisse Group AG (>> Credit Suisse Group AG) and UBS AG (>> UBS AG).

The SEC is examining whether the banks or their employees violated anti-bribery laws by hiring relatives of well-connected officials, the WSJ reported. (http://r.reuters.com/tyc29v)

The regulator has not accused any of the banks of wrongdoing, the paper said.

Andrew Williams, a spokesman for Goldman Sachs, declined to comment on the report, as did Danielle Romero-Apsilos, a Citigroup spokeswoman, and Jack Grone, a spokesman for Credit Suisse.

John Nester, a spokesman for the SEC and representatives at UBS and Morgan Stanley did not immediately respond to requests for comment outside regular U.S. business hours.

U.S. authorities' interest in the hiring practices of banks operating in Asia first came to light in August, when media reports said that the SEC was looking at whether JPMorgan Chase & Co's (>> JPMorgan Chase & Co.) Hong Kong office hired the children of powerful heads of state-owned companies in China with the express purpose of winning underwriting business and other contracts.

The commission is seeking data on the banks' recruiting in Asia, including lists of employees hired due to referrals from foreign officials and clients, the Journal report cited unnamed people close to the inquiry as saying.

In March, JPMorgan's chief executive for China investment banking, Fang Fang, quit the bank after his name emerged in the investigation.

The SEC had last year sent notices to some banks as part of an industry-wide investigation about whether the banks had special programs dedicated to relatives of influential officials.

The SEC inquiry is focused on potential breaches of the Foreign Corrupt Practices Act, which bars U.S. companies from giving money or other items of value to foreign officials to win business.

(Reporting by Anannya Pramanick and Aman Shah in Bangalore; Editing by Mohammad Zargham)