Mexico peso sinks to 1-month low on downgrade bets

* Peso hits one-month low, hurt by downgrade worries

* Mexican currency declines 1.6 percent this week

* Stocks gain as U.S. unemployment seen nearing ceiling (Adds closing stock prices, debt movement)

MEXICO CITY, Nov 6 (Reuters) - Mexico's peso sank to a one-month low on Friday, hurt by concerns tax reforms passed last weekend will not be enough to stave off a downgrade of the country's debt.

The peso MXN=MEX01 lost 0.97 percent to 13.415 per U.S. dollar, closing out its worst week in a month and a half with around a 1.6 percent loss.

The IPC stock index .MXX closed up 0.45 percent to 29,868.62 after U.S. employment figures offered a few glimmers of hope for Mexico's top trading partner. The IPC gained 4.3 percent this week.

Last weekend, Mexican lawmakers finalized a watered-down version of President Felipe Calderon's fiscal reform package, which aims to raise taxes and help reduce Mexico's dependence on its waning oil industry.

Many analysts say the reforms are not deep enough to satisfy Wall Street ratings agencies that threaten to downgrade Mexico's debt unless the government widens its tax base.

"The interpretation is that the revenue law could result in a downgrade, and foreigners are deciding to put their money elsewhere while the uncertainty continues," said Juan Jose Resendiz, an analyst at Arka brokerage firm in Mexico City.

Standard & Poor's and Fitch Ratings, which both have assigned Mexico a negative outlook, have said they will wait to issue any decisions until lawmakers approve the spending side of the budget, expected later this month.

On Friday, data showed the U.S. unemployment rate jumped to a higher than expected 10.2 percent, the worst in more than 26 years. The data initially spurred losses in U.S and Mexican equities, but closer inspection of the report showed payroll losses kept declining.

"The market is looking at this as a sign that U.S. unemployment could be nearing a ceiling," Resendiz said.

Mexico is counting on a rebound in U.S. consumer demand for its exports to help pull out of the worst local recession since the 1930s.

Shares in miner Grupo Mexico (GMEXICOB.MX) rose 2.04 percent to 29.01 pesos cement maker Cemex (CMXCPO.MX) gained 1.65 percent to 14.78 pesos.

The government's 10-year peso bond MX10YT=RR bid down 5 basis points to 8.01 percent as falling yields on U.S. Treasuries made higher-yielding debt more attractive to yield-hungry investors. (Reporting by Michael O'Boyle; Editing by Andrew Hay)