US STOCKS-Wall Street jumps 1 pct, S&P on track for 5-day rally

* China exports handily top expectations, boosting materials

* Senate sets test vote for Syria, measure's support unclear

* Koch Industries to buy Molex for about $7.2 billion

* Indexes up: Dow 1 pct, S&P 500 1 pct, Nasdaq 1.2 pct

By Ryan Vlastelica

NEW YORK, Sept 9 (Reuters) - U.S. stocks rose 1 percent in a broad rally on Monday, putting the S&P 500 on track for a fifth straight day of gains as upbeat data from China boosted sentiment about the health of the global economy.

All 10 S&P sectors were higher, with merger activity and easing concerns about Syria giving investors further reason to buy. About 77 percent of companies traded on the New York Stock Exchange rose.

Basic materials shares led the day's gains after China's August exports handily beat market expectations while consumer inflation held steady. U.S. Steel Corp jumped 3 percent to $19.44 while Peabody Energy (NYSE: BTU - news) rose 2.6 percent to $18.69.

"This is more proof that the Chinese government's attempts to stabilize the country's economy are helping, and that really got us up and running," said Donald Selkin, chief market strategist at National Securities in New York.

Equities added to their gains in afternoon trading as it appeared less likely that a resolution authorizing military strikes against Syria would easily pass the U.S. legislature. Geopolitical uncertainty related to Syria has been a major market driver in recent weeks, with investors especially concerned about the potential impact on the oil market.

U.S. Senate Democratic Leader Harry Reid set a test vote for later this week, but it was unclear whether the measure would attract enough backing to clear anticipated procedural roadblocks.

"Every poll shows it would be very difficult for Obama to get authorization, and that might be enough to delay any action or at least make the action more cautious," said Selkin, who helps oversee $3 billion in assets. "Both of those would give the market a leg up."

Separately, a Russian proposal to place Syria's chemical weapons under international control was welcomed by the government in Damascus, who praised the Kremlin (Berlin: KMLK.BE - news) for seeking to "prevent American aggression."

The Dow Jones industrial average was up 151.87 points, or 1.02 percent, at 15,074.37. The Standard & Poor's 500 Index was up 15.88 points, or 0.96 percent, at 1,671.05. The Nasdaq Composite Index was up 44.60 points, or 1.22 percent, at 3,704.61.

The S&P was on track for its best day since Aug. 1 and rose above its 50-day moving average for the first time since Aug. 23, a sign of positive near-term momentum. The index has risen for five straight sessions, rising nearly 2 percent over that period.

Deal news gave a further boost to market confidence. Koch Industries agreed to buy electronic connectors maker Molex for about $7.2 billion. Ares Management LLC and the Canada Pension Plan Investment Board reached a deal to buy privately owned U.S. luxury retailer Neiman Marcus for $6 billion.

Molex shares surged 31.4 percent to $38.54 as the S&P's top gainer. Tech shares gained 1.2 percent.

Investors are also keeping an eye on U.S. Federal Reserve policy. Most market participants expect the central bank to announce it will start to pare back its accommodative monetary policies next week.

Shares of homebuilders rallied on bets of a cap on mortgage rates, which have risen recently, as U.S. Treasuries yields fell from two-year highs as more investors bet the Fed may reduce bond purchases by less than previously thought. The PHLX housing sector index jumped 3.4 percent to its highest in a month with PulteGroup (NYSE: PHA - news) up 7.1 percent at $16.57.

Isis Pharmaceuticals Inc (Stuttgart: 881866 - news) jumped 11.6 percent to $31.17 after the company said it had reached a collaboration with Biogen Idec Inc (NasdaqGS: BIIB - news) on treatments for neurological disorders. Biogen shares edged up 0.6 percent to $226.55.

On the downside, Tenet Healthcare (NYSE: THC - news) shares fell 5.7 percent to $37.57. Barclays Capital on Monday downgraded the health care sector to "market weight" from "overweight," saying it wanted to take profits following steep gains this year.