* U.S. GDP underpins sentiment * Parliament session may provide catalyst - analysts * SoftBank's M&A news has limited impact on stock By Ayai Tomisawa TOKYO, Sept 29 (Reuters) - Japan's Nikkei share average rose on Monday morning after the weak yen supported sentiment, while risk taking was buoyed after the U.S. economy grew at its fastest pace in 2-1/2 years in the second quarter.
The Nikkei share average gained 0.5 percent to 16,310.63 in mid-morning trade after falling 0.9 percent on Friday.
"There is more upside to the Japanese market considering its valuations. There are major events this week so investors are cautiously optimistic," said Shigemitsu Tsuruta, senior strategist at SMBC Friend Securities, adding that long-term risk appetite should be supported by a U.S. economic recovery and the weak yen for the time being.
He said that for this week, gains may be limited as investors want to see U.S. jobs data due on Friday before they take more bets.
The U.S. economy grew at its fastest pace in 2-1/2 years in the second quarter with all sectors contributing to the jump in output in a bullish signal for the remainder of the year.
The dollar added about 0.1 percent to 109.36 yen, nearing last Friday's six-year peak of 109.54 yen.
Exporters were strong, with Honda Motor Co rising 0.6 percent, Advantest Corp soaring 2.7 percent and Canon Inc advancing 0.8 percent.
SMBC Friend's Tsuruta added that an extraordinary Diet session during which the ruling parties hope to pass bills reinvigorating local economies starting on Monday could provide a catalyst to the market.
"Depending on bills being taken up, stocks related to related areas may rise such as robotics," Tsuruta said.
News that SoftBank Corp was in talks to acquire DreamWorks Animation (SKG DWA.O) provided little reaction to the telecom giant's stock price as investors have yet to digest the implication of the reported merger.
SoftBank's shares were down 0.9 percent, easing from positive territory earlier.
"SoftBank's core business is mobile communications. It's not clear what the company wants to do in the animation area," said Mitsushige Akino, chief fund manager at Ichiyoshi Asset Management.
Bucking the strength, Aeon Co fell 1.8 percent after the Nikkei business daily reported that the supermarket operator's operating profit in the March-August period likely dropped by 40 percent on year to about 42 billion yen.
The broader Topix added 0.5 percent to 1,338.35, and the JPX-Nikkei Index 400 gained 0.5 percent to 12,177.83.
(Editing by Jacqueline Wong)