SYDNEY, Dec. 29 (Xinhua) -- The Australian stock market opened lower on Friday amid muted trading that marked the last week of the year following the highs of the past few months.

At 10:36 (AEDT), the benchmark S&P/ASX200 index was down 20.3 points or 0.33 percent at 6,067.8, while the broader All Ordinaries index slipped 19.7 points or 0.32 percent at 6,169.7 points.

Aussie shares had closed the previous day very near 10-year highs on the back of momentum building up in the last three months, even as lower trading volumes marked the post-Christmas period leading up to the year-end festivities.

The country's big banks opened lower on Friday, with ANZ down 0.35 percent, Commonwealth Bank of Australia dipping 0.08 percent, National Australia Bank slipping 0.17 percent and Westpac falling 0.48 percent.

Mining giant BHP Billiton opened 0.78 percent higher and rival Rio Tinto gained 0.69 percent. Newcrest Mining lifted 0.92 percent while Oil Search dipped 0.06 percent.

Supermarket chain Wesfarmers slipped 0.47 percent and rival Woolworths fell 0.69 percent.

Qantas was down 0.6 percent, telecom giant Telstra fell 0.54 percent and biomed group CSL edged 0.11 percent lower.