TOKYO, Oct 7 (Reuters) - Japanese shares jumped on Thursday after eight straight sessions of falls, as signs of progress in U.S. political negotiations over debt ceiling provided market participants a catalyst for bargain-hunting. Investors snatched up growth and cyclical shares that had been beaten down recently on worries central banks might pare stimulus faster than expected due to rising concerns about higher inflation worldwide. The Nikkei average rose 1.55% to 27,956 while the broader Topix gained 0.7% to 1,955.50. The Topix index of growth shares was up 1.2%. Internet firm Z Holdings rose 3.4% while robot maker Fanuc gained 2.6%. MSCI’s semiconductor-related shares index rose 2.2%, with Tokyo Electron up 2.2% and Disco adding 2.7%. Volatile shippers also bounced back, with their index rising 2.9% after having lost almost a third of its value in the previous eight sessions. Elsewhere, Welcia rose 6.6% after the drugstore chain operator posted brisk earnings results in the three months to August. But Aeon lost 2.8% after the supermarket chain operator’s earnings disappointed investors. Japan Post Holdings lost 1.7% after the government said it would sell up to 1.03 billion shares, which at Wednesday’s closing price would be worth 952 billion yen ($8.52 billion). To reduce the impact, the firm announced a share buyback of up to 100 billion yen. (Reporting by Hideyuki Sano; Editing by Subhranshu Sahu) Our Standards: The Thomson Reuters Trust Principles.