Australia shares slump 1.4 pct from six-year highs in broad selloff

* ASX 200 slumps 1.4 percent from 6-year highs in broad selling

* 11 shares higher, 183 shares lower, 6 shares unchanged (Adds analysis, quotes, stocks on the move)

By Thuy Ong and Gyles Beckford

SYDNEY/WELLINGTON, Aug 1 (Reuters) - Australian shares tumbled 1.4 percent from six-year highs on Friday in a sharp fall across all sectors after Wall Street tumbled overnight as strong U.S. economic data stoked concerns the Federal Reserve may start its rate-tightening cycle sooner than expected.

The S&P 500 stock index posted its worst daily fall since April and its first monthly drop since January overnight.

Top 20 stocks on the ASX 200 floundered, and all 'Big Four' banks fell, with top lender Commonwealth Bank of Australia (Other OTC: CBAUF - news) losing 1.2 percent, while Westpac Banking Corp, Australia's second-biggest bank by market value, fell 1.6 percent.

Among defensives, retailer Wesfarmers Ltd was down 1.7 percent, while blood products maker CSL Ltd (Other OTC: CMXHF - news) tumbled 2.3 percent, and top telecommunications provider Telstra Corporation Ltd declined 0.8 percent.

The S&P/ASX 200 index slumped 80 points to 5,552.9 by 0204 GMT, its biggest one-day percentage drop since mid-March.

The benchmark index touched a fresh six-year high of 5,644.2 in the previous session, underscored by a rally in global equities and optimism of recovery in China, Australia's largest export market. It added 0.2 percent on Thursday, and for the month jumped 4.4 percent, its highest monthly percentage gain since July 2013.

"Australian investors will be aware that last night's sell-off now makes tonight's U.S. non-farm payroll number a particularly (high) stakes number for stock markets," said Ric Spooner, chief market analyst at CMC Markets in a note to cients.

"It has the capacity to either confirm or overturn the emerging market consensus that the Fed is getting closer to lifting interest rates."

Elsewhere, China's official Purchasing Managers' Index rose to 51.7 in July from 51 in June, hitting a 27-month high, while China's final HSBC PMI hit an 18-month peak in July of 51.7.

The data failed to excite investors, who continued to sell out of resource stocks with global miners BHP Billiton Ltd and Rio Tinto Ltd (Xetra: 855018 - news) declining 0.9 percent and 1.4 percent.

ResMed (NYSE: RMD - news) fell 3.8 percent after the medical device maker said its fourth quarter results were weaker than anticipated.

New Zealand stocks followed the global sell down, with the benchmark NZX-50 index down 38.9 points or 0.7 percent lower at 5,129.03. It had opened more than 1 percent lower, its biggest single session decline since mid-December.

Price drops were the order of the day, with top stock Fletcher Building (NZSE: FBU.NZ - news) down 1.1 percent to NZ$9.02, and similar-sized falls for fellow top-10 stocks Sky Television and Contact Energy (NZSE: CEN.NZ - news) .

Software (Xetra: 330400 - news) company Xero was down 2.5 percent after reporting a lift in revenue and expenses, and a bigger draw on its development funds.

The biggest fall was for newly listed software company Gentrack Group , which fell 12.4 percent to NZ$2.25, after warning it expected a lower profit because of a dispute with a customer.

However, among the handful of rising stocks was outdoor clothing retailer Kathmandu, rising 3.3 percent to NZ$3.44. It said full-year profit was not expected to fall as much as previously feared because of a lift in sales caused by a late cold snap. On the ASX, Kathmandu soared 4 percent to A$3.14. (Editing by Eric Meijer)