Share prices closed higher, with the Nikkei 225 reaching a four-year high, as investors remain positive about the outlook for the Japanese economy, pushing aside concerns about the impact of high oil prices, dealers said. The blue-chip Nikkei 225 Stock Average closed up 93.03 points or 0.7 pct at 12,600.00, its highest level since July 5, 2001. The broader-based TOPIX index of all First Section issues rose 5.46 points or 0.4 pct to 1,282.79. Over the week, the Nikkei 225 added 1.3 pct while the TOPIX advanced 0.8 pct. Winners led losers today 842 to 662, with 155 issues unchanged. Volume reached 1.87 bln shares, down from 2.00 bln shares at yesterday's close. Oil prices remained close to 70 usd a barrel in Asian trading hours. Despite persistently high oil prices, equity investors here are optimistic because they believe the economy is recovering and that corporate earnings will be stronger in the next quarter, dealers said. This upbeat estimate was underpinned by Wednesday's report on industrial output, which said that although it fell 1.1 pct in July from the previous month, it will rise 2.3 pct in August and September. "The tangible impact of high oil prices, such as rising prices, is likely to surface when the weather cools down as autumn nears," said Ryuta Otsuka, a strategist at Toyo Securities. "But this may even turn out to be positive for the Japanese economy as it has been suffering from long-lasting deflation," Otsuka said. Moreover, the current oil price level is not a threat as "Japanese industry estimates that even if crude oil prices stay at 70 usd a barrel, current profits would be pushed down only about 0.5 pct," Otsuka said. Oil-related shares ended higher. Showa Shell Sekiyu KK closed up 55 yen or 4.2 pct at 1,358, Nippon Oil jumped 31 yen or 3.4 pct to 931, TonenGeneral Sekiyu KK surged 26 yen or 2.1 pct to 1,248 and Cosmo Oil edged up 7 yen to 560. The high-tech sector also gained, with Rohm up 30 yen or 10,200, Kyocera inching up 50 yen to 7,770, Nikon jumping 42 yen or 3.2 pct to 1,352 and Tokyo Seimitsu rising 40 yen to 4,850. In the machinery sector, Fanuc rose 60 yen to 8,500, Komatsu surged 41 yen or 3.2 pct to 1,308, Murata Manufacturing gained 80 yen to 5,880 and Kubota soared 11 yen to 713.