* Renesas bounces, up 30 pct; trader says oversold * Olympus up 6 pct on report of tie-up * Spain worries continue to depress sentiment TOKYO, May 30 (Reuters) - Japan's Nikkei inched down early on Wednesday, with speculation of China stimulus steps failing to inspire risk taking, although troubled chipmaker Renesas Electronics Corp staged a dramatic rebound and Olympus Corp soared on a reported tie-up. The Nikkei share average slipped 0.8 percent to 8,584.78, while the broader Topix index fell 1 percent to 719.86 by 0145 GMT. Softbank Corp put on a solid 3 percent and was the top traded stock by turnover after Deutsche Securities upgraded the telecommunication company's rating to "buy" from "hold" and raised its target price to 2,810 yen from 2,570 yen, saying it had an impressive subscriber growth rate. "The market reacted well to signs that a Chinese stimulus programme may be coming yesterday, but now that's priced in it's back to worrying about the euro zone," said Hideyuki Ishiguro, assistant manager of investment strategy at Okasan Securities. "The market is tired of waiting for the Greek election, so the focus is shifting to Spain." Exporters remained under pressure as the yen firmed to a four-month high against the euro after Spain's borrowing costs rose on Tuesday towards the 7 percent level that led other countries to seek a bailout. "Japanese stocks are cheaper than ever, but buyers will be put off by the strong yen," said Hiroichi Nishi, equity general manager at SMBC Nikko Securities. Renesas Electronics soared 30 percent, bouncing back after its share price was slashed in half this month and the troubled chipmaker said it plans to raise 100 billion yen ($1.3 billion) to pay for a proposed restructuring. "It has been oversold ... They're hoping to get some capital injection, significantly lessening the downward pressure," a dealer at a European brokerage said. Olympus Corp also jumped, gaining 5.5 percent after the Asahi newspaper reported that it was seeking a capital tie-up worth tens of billions of yen with either Sony Corp or Panasonic Corp. Both companies fell 2 percent on the news that they could be associated with scandal-ridden Olympus. The Nikkei was out of "oversold" territory, with its 14-day relative strength index at 31.3, but market analysts said it would encounter strong resistance on the upside as most buying was short-covering and buying on dips. "There won't be any reason for buying in earnest until the euro zone calms down, but right now it's moving in an ominous direction," Ishiguro of Okasan Securities said. The Nikkei is down 16 percent from its year high of 10,255.15 on March 27 and has posted a weekly loss for eight consecutive weeks, its worst run for 20 years, on a deepening euro zone debt crisis and concerns about the slowing global recovery.