Mexico peso, stocks tumble on global growth doubts

(Updates prices, adds analyst comment)

MEXICO CITY, Aug 17 (Reuters) - Mexico's peso sank on Monday and stocks suffered their biggest drop in eight weeks as signs of weakness in Asia stoked worries that this year's rally in emerging markets has outpaced real growth prospects.

The peso had its biggest one-day slide since July 7 to trade 0.91 percent weaker at 12.9629 per U.S. dollar.

The IPC stock index declined 1.93 percent to 27,317, its biggest single-session drop since June 22.

Global equity markets fell and emerging market currencies weakened after investors were unnerved by a steep slide in Shanghai stocks on worries that Chinese authorities could restrict lending.

Growth data in Japan showed the world's No. 2 economy had climbed out of recession as exporters rebuilt inventories, but officials cited weakness in capital spending and doubts about how long a rise in consumer spending would last.

"The data from Japan, the apparent problems in China and the doubts whether the recovery is sustainable are all elements to justify taking profits," said Juan Jose Resendiz, head of analysis at Arka brokerage in Mexico City.

Resendiz said profit-taking would likely continue this week, but the IPC index would find support at around 26,800 points.

Investors still fretted over data from Friday that showed U.S. consumer confidence fell in early August. The United States is Mexico's top trading partner, and the recovery from a deep recession depends on a rebound in U.S. consumer demand.

"Investors are every day assigning more importance to indicators on the spending side and these -- at least at the beginning of the third quarter -- have been disappointing," wrote Salvador Moreno, an economist at ING in Mexico City, in a note to clients.

After lagging gains in other emerging markets, Mexico's peso has outperformed peers in recent weeks on bets it will benefit the most from a U.S. recovery.

Resendiz said further flows from investors counting on a surprisingly solid U.S. recovery could keep supporting the peso in coming weeks.

Some analysts expect a further selloff of riskier assets to weigh on the peso. ING's Moreno said the peso could be as weak as 13.30 per U.S. dollar by the end of August.

In stock trading, America Movil, Latin America's top wireless operator, lost 1.26 percent to 29 pesos, while copper miner Grupo Mexico shed 3.65 percent to 18.73 pesos.

Shares in Cemex gained 1.23 percent to 14.03 pesos after the world's No. 3 cement maker said it had until next June to raise $1 billion in equity as part of a $15 billion debt restructuring that has allayed fears of default.