Toshiba Corp. said Thursday that operating profit in the first half of the fiscal year hit a 28-year high, driven by a strong performance from the memory chip business it is trying to sell to eliminate its negative net worth.

Toshiba said operating profit at the end of the April-September period had surged to ¥231.8 billion from ¥93.2 billion last year, the highest since 1989.

This is largely due to strong growth in the chip industry, which saw sales surge 39 percent from the same period last year.