TOKYO, April 1 (Reuters) - Japan's Nikkei share average fell sharply on Monday, dropping below the key 40,000 mark as investors sold stocks to book profits on the first day of the country's financial year.

The Nikkei fell 1.5% to 39,765.22 by the midday break after opening 0.7% higher. The broader Topix was down 1.88% at 2,716.47.

"Institutional investors typically sell stocks to book profits on the first day of the financial year," said Shoichi Arisawa, general manager of the investment research department at IwaiCosmo Securities.

The Nikkei is up 19% in 2024 and scaled the 40,000 mark to hit record highs in March, after a steady 54% rise since early 2023.

Chip-related Tokyo Electron and Advantest lost 3.34% and 4.14% respectively, becoming the biggest losers on the Nikkei.

Toyota Motor fell 4.22%. (Reporting by Junko Fujita; Editing by Varun H K)