Asian stocks fell, with a regional benchmark retreating after a record 10-week advance, as oil neared a nine-month high and continued concern that Greece will not be able to avoid a default spurred investors to lock in gains.

Korean Air Lines Co, the nation's biggest carrier by market value, sank 5.3 percent in Seoul. Esprit Holdings Ltd, a clothier that gets most of its revenue from Europe, slid 3 percent in Hong Kong. Sony Corp, Japan's No 1 exporter of consumer electronics, gained 1.2 percent in Tokyo as the yen fell to a nine-month low against the dollar, boosting the earnings outlook for the country's exporters.

The MSCI Asia Pacific Index slid 0.8 percent to 126.92 as of 5:41 pm in Tokyo, accelerating its drop after Moody's Investors Service said the risk that Greece will default "remains high". The index advanced for a 10th week last week, its longest run of gains since its inception in 1988. Shares rose amid confidence China will ease monetary policy and signs the US economy is improving.

"Oil prices are definitely a concern," Bharat Joshi, who helps manage $5 billion at Kuala Lumpur-based Aberdeen Asset Management Sdn, said in a telephone interview on Monday. "People are worried about inflation trickling into the economy. The market has also risen quite dramatically. The issue with Greece and Europe continues to be in the background."

Japan's Nikkei 225 Stock Average slipped 0.1 percent after swinging between gains and losses. Sony gained 1.2 percent to 1,760 yen ($21.89), while Honda Motor Co, Japan's second-largest carmaker by market value, rose 1.6 percent to 3,140 yen.

The yen touched 81.67 per dollar on Monday, the lowest level since May 31. A weaker yen boosts exporters' overseas earnings when repatriated.

"It's a huge fuel for Japanese exporters if the yen can maintain or continue to depreciate from current levels given it's been such a substantial headwind," said Tim Schroeders, who helps manage $1 billion in equities at Pengana Capital Ltd in Melbourne.

The MSCI Asia Pacific Index gained 12 percent this year through Friday, compared with an 8.6 percent increase by the S&P 500 and an 8.3 percent advance by the Stoxx Europe 600 Index. Stocks in the Asian benchmark are valued at 14.9 times estimated earnings on average, compared with 13.1 times for the S&P 500 and 11.1 times for the Stoxx 600.

Australia's S&P/ASX 200 Index slid 0.9 percent. Singapore's Straits Times Index fell 0.8 percent. South Korea's Kospi Index retreated 1.4 percent. Crude for April delivery slid as much as 0.8 percent on Monday. Oil gained 1.8 percent to $109.77 a barrel in New York on Friday, advancing for a seventh day, the longest stretch since January 2010.