Standard & Poor's said it may cut the ratings of 22 Japanese companies, including corporate giants like Nippon Telegraph & Telephone Corp, Toyota Motor Corp and Mitsubishi Corp. "Pressures building in the Japanese economy and in the nation's financial system pose a growing, broad-based threat to the credit quality of Japan's industrial sector," S&P Said in a statement.

"Of particular concern is how firms can maintain their competitiveness and adequate financial profiles to cope with the risks of deflation, contracting demand, and a financial system under strain," S&P Said.

Japan, the world's second largest economy, is suffering from a severe recession, which has a weak banking system at its root. Economic growth has slowed around the world, and bank and corporate credit ratings globally are underpressure.

In an unprecedented move, Japan's own sovereign rating was cut by another credit rating agency, Fitch IBCA, last week. Fitch IBCA cited a worsening economy, chaos over how to solve a banking crisis and mounting public debt as reasons to remove Japan's foreign currency bonds from the top triple-A class.

S&P Said the global economic down turn made the outlook for Japanese companies worse. "The recent economic downturn in the Asian region outside Japan and fears of a slowdown in other major export markets are exerting pressure on earnings from outside Japan," S&P Said.

"The prolonged nature of the downturn has sparked growing concerns over the companies' earnings-generation ability. Consequently, the companies' ability to generate sufficient operating cash flow to fund capital spending requirements and meet debt maturities has become critical," it said.

S&P Plans to review the individual ratings of the 22 Japanese companies and decide on their rating levels in the coming months.

Othercompanies among the 22 named by S&P were Japan Airlines Co, carmakers Toyota Motor Corp and Nissan Motor Co> and electronics and computer maker NEC Corp.