Asian stocks hit a fresh 10-month peak on Friday, with Hong Kong vaulting back to levels last seen before the collapse of Lehman Brothers as investors rushed into equities following upbeat corporate earnings around the world.

But gains were limited and higher-yielding currencies lost ground as some investors moved to book profits on the run-up this week, with some technical signals flashing warning signs that the risky asset surge may be due for a reversal.

Hong Kong's Hang Seng index <.HSI> pushed above the 20,000 mark at the start of trade to hit its highest since early September last year, making Asian markets among the first to retake levels last seen before Lehman's demise.

The yen pushed higher on a dip in the Australian and New Zealand dollars, which retreated along with oil prices and other commodities. Copper prices recoiled from a nine-month high.

South Korea reported its economy expanded at its fastest pace since 2003 in the second quarter, pushing bonds lower and buoying stocks.

South Korea's Samsung Electronics <005930.KS>, the world's top maker of memory chips and LCD screens, reported its best quarterly profit in 2- years. But Samsung's shares edged up just 0.2 percent, lagging the broader market's rise. Seoul's benchmark KOSPI index <.KS11> was up 0.5 percent.

Gains are not so robust as markets have been on uninterrupted gains for several days now, said Kim Young-june, a market analyst at SK Securities in Seoul.

The relentless surge in Asian shares has taken the benchmark MSCI index of Asia-Pacific shares outside Japan up 73 percent from its March lows, stoking some worries among analysts that an asset bubble may be forming as investors rush to take part.

The MSCI benchmark for Asia <.MIAPJ0000PUS> was up 0.4 percent on the day and 4.5 percent on the week, tracking the weekly gain in the MSCI index of world stocks <.MIWD00000PUS>.

On Thursday the U.S. S&P 500 <.SPX> jumped 2.3 percent after breaking through technical resistance.

But Microsoft Corp , Amazon.com Inc and American Express posted disappointing quarterly results after the bell, sending their stocks lower and adding a fresh note of caution in Asia. <.N>

A sudden rebound in property markets in China, Hong Kong and other parts of Asia has already stirred concerns about inflationary pressures.

The Shanghai Securities News reported on Friday that an unpublished Chinese government report said speculative demand from property started to emerge in May and June, but that officials were holding off from changing policy for now.

The Shanghai Composite index <.SSEC> climbed 1 percent to a 13-month intraday peak, taking this year's gains to 85 percent.

Hong Kong's Hang Seng <.HSI> gained 0.6 percent to 19,936 and briefly rose above 20,000, the highest intraday level since September 10 -- just a few days before Lehamn filed for bankruptcy and sparked a plunge across global markets.

Japan's Nikkei average <.N225> rose 1.5 percent and was on track for an eighth straight day of gains. Panasonic Corp <6752.T> jumped nearly 7 percent after JPMorgan raised its rating on the stock.

YEN FIRMS ON PROFIT TAKING IN RISKIER ASSETS

In currencies, the yen pushed higher as market players took profits on the jump in the Aussie and kiwi against the low-yielding Japanese currency.

The dollar was down 0.4 percent at 94.65 yen, while the Aussie dipped 0.3 percent to 77.00 yen. The euro was little changed against the dollar at $1.4150.

The dollar's slight dip helped boost gold prices $1.35 an ounce to $948.50.

Korea government bond futures shed 10 ticks to 109.70, back near a one-month low hit the previous day, after the solid GDP figures. But analysts cautioned that the recovery was not strong enough yet to be self-sustaining.

South Korea is unlikely to change its policy stance. The recovery is not on solid ground yet, said Daniel Soh, currency strategist at 4Cast in Singapore. We may see some monetary fine-tuning, rather than tightening, in the second half.

(Additional reporting by Jungyoun Park in Seoul)

(Editing by Kim Coghill)