TOKYO, April 28 (Xinhua) -- Tokyo stocks closed mixed Tuesday, with the benchmark Nikkei stock index retreating as investors locked in gains in heavyweight technology shares after recent surges, while the Topix index managed to hold firm.

The 225-issue Nikkei Stock Average ended down 619.9 points, or 1.02 percent, from Monday at 59,917.46. The broader Topix index finished 36.91 points, or 0.99 percent, higher at 3,772.19.

On the top-tier Prime Market, the main gainers were consumer credit and construction issues, while information and communication and electric appliance were notable decliners.

Shares related to artificial intelligence and semiconductors dragged down the Nikkei, as investors grew cautious about overheating after the benchmark index hit fresh intraday and closing highs the previous day on strong tech gains. ■