TOKYO, Sept 6 (Reuters) - Japanese companies, especially

those considering investing in the U.S., are closely watching

Washington's review of Nippon Steel's ( NISTF ) proposed $15

billion acquisition of U.S. Steel, Japan's biggest

business lobby Keidanren said on Friday.

"We sincerely hope that the review procedure (in the United

States) will be conducted with the utmost integrity and fairness

in accordance with the law," Keidanren said in a statement.

The deal, facing growing bipartisan political opposition

ahead of the U.S. presidential election, has caught the

attention of Japanese companies as Washington is Tokyo's closest

ally and Japan is the biggest foreign investor into the U.S.

Sources told Reuters on Wednesday the White House was close

to announcing that President Joe Biden will block the Japanese

company's bid for U.S. Steel on national security risks.

Keidanren's statement comes after the Japan-U.S. Business

Council, a Washington, D.C.-based industry group representing

major Japanese firms, said on Thursday it was seriously

concerned by the reports Biden was going to block the sale.