Tokyo stocks up 0.81 percent by noon

The benchmark Nikkei 225 index at the Tokyo Stock Exchange added 69.12 points to 8,644.28 by the lunch break. The broader Topix index of all first-section issues gained 0.59 percent, or 4.33 points, to 742.34.

"It's unknown how the summit will go, but so far we see signs that eurozone nations are working together," Hideyuki Ishiguro, supervisor at investment strategy at Okasan Securities, said.

"That's giving the market some sense of relief," he told Dow Jones Newswires.

The two-day talks, starting on Thursday, are seen as crucial to containing the debt crisis that has gripped the eurozone and saving the single currency.

A call by French President Nicolas Sarkozy and German Chancellor Angela Merkel to set uniform tough budget standards across the eurozone raised hopes that the region would take decisive moves to end its fiscal crisis.

The pair backed automatic sanctions against member states whose budget deficits rise above three percent of gross domestic product.

US stock markets were mixed with the Dow Jones Industrial Average closing 0.43 percent higher on Tuesday, while the Nasdaq Composite lost 0.23 percent and the broader S&P 500 gained 0.11 percent.

The euro fetched $1.3423 and 104.32 yen in Asian trade Wednesday, compared with $1.3397 and 104.14 yen in New York late Tuesday.

The dollar stood at 77.72, compared with 77.70 yen.

Scandal-hit Olympus fell 6.89 percent to 1,108 yen on profit-taking after six consecutive days of gains.

The company was due to hold a news briefing later Wednesday to discuss an independent report that said two former presidents backed a plan to cover up massive losses stretching back to the 1990s.