Japan stocks edge lower on U.S. job worries, Sony

(Updates to midafternoon)

TOKYO, Feb 1 (Reuters) - Japanese shares edged lower on Friday as investors sold stocks amid worries about U.S. jobs data due later in the day and after electronics giant Sony Corp (6758.T) lowered its profit forecast.

Mizuho Financial Group (8411.T) came under pressure after announcing that its losses on subprime-related investments had ballooned, while a sharp fall in Shanghai stocks .SSEC helped further dampen investor appetite for shares.

Market participants said dealers were closing out positions ahead of U.S. jobs data given lingering concerns over the course of the U.S. economy. "Wall Street may have risen yesterday, but many of the economic indicators that have been coming out recently are poor, raising concerns about the jobs data," said Nagayuki Yamagishi, a strategist at Mitsubishi UFJ Securities.

The U.S. market rallied after MBIA Inc (MBI.N), the No. 1 U.S. bond insurer, said it had enough cash to run its business of guaranteeing payments on corporate and municipal bonds. Standard & Poor's also told the company it had enough capital to keep its triple-A rating, MBIA executives said. [.N]

"While this news may have helped financial shares, there's still a lot of uncertainty about bond insurers overall. Add in yesterday's disappointing results from Google, and you really can't say the U.S. market has settled down," Yamagishi said.

At 0445 GMT the benchmark Nikkei .N225 was 0.3 percent lower at 13,546.03. The broader TOPIX was down 0.5 percent at 1,339.51.

Sony slid after HSBC cut its rating to "neutral" from "overweight", citing the risk that a weakening U.S. economy and the strengthening yen could sap future profits at the maker of PlayStation 3 game consoles and Vaio PCs.

It crawled slightly from earlier lows but was still down 5.9 percent at 4,910 yen.

In the banking sector, Mizuho fell 4.6 percent to 475,000 yen and industry leader Mitsubishi UFJ Financial Group (8306.T) dipped 3.7 percent to 995 yen. Sumitomo Mitsui Financial Group (8316.T) was close behind, down 2.6 percent at 816,000 yen.

Mizuho said on Thursday that its subprime-related losses came to 345 billion yen in the nine months to December, more than double its previous estimate for the entire financial year, and it lowered its profit forecast for a second time. (Reporting by Elaine Lies; Editing by Mike Miller)