* Benchmark solidly above 25-day moving average
* Exporters gain, lifted as yen falls to one-month low
By Lisa Twaronite
TOKYO, Oct 13 (Reuters) - Japan's Nikkei rose to a four-week high on Thursday on hopes that Europe will come up with actual measures to support Greece and shore up European banks.
Shares in major exporters such as Sony Corp , which were sold off during the market downturn until earlier this month on worries about the global economy, rose sharply as players bought them back on tentative signs of progress in the response to the European debt crisis.
The Nikkei benchmark climbed 1 percent to 8,829.64, while the broader Topix index advanced 0.8 percent to 759.82.
Resistance looms at around 8,870, a high hit in mid-September, given lingering doubts over the health of the European financial system and the global economy. But the benchmark remained above its 25-day moving average of 8,638.
It also broke above its 50-day moving average of 8,829 for the first time since Aug. 4, although it didn't sustain a break at this level.
"Resistance points don't tell the complete story, because so much of the market's direction depends on the progress of the European debt plan and U.S. earnings," said Hiroaki Osakabe, a fund manager at Chibagin Asset Management Co.
Analysts say gains could be limited ahead of more U.S. earnings reports such as from J.P. Morgan later on Thursday, particularly since earnings guidance so far from companies such as Alcoa and PepsiCo has not been strong.
The yen's slide to a one-month low also supported exporters.
TDK rose 5.7 percent to 2,837 yen, while Panasonic climbed 2.7 percent to 761 yen. Sony added 3.1 percent to 1,564 yen.
Shares in camera and endoscope maker Olympus were up 5.3 percent to 2,498 yen, after Goldman Sachs analyst Toshiya Hari upgraded the stock from neutral to buy, setting a 24-month target price at 3,800 yen, compared with a previous 12-month target price of 2,400 yen. (Additional reporting by Hideyuki Sano; Editing by Joseph Radford)