SAN DIEGO — Qualcomm fell short of Wall Street estimates for fourth-quarter smartphone chip sales on Wednesday, sending its shares down more than 6% in extended trading as investors weighed sluggish demand and declining Apple-related revenue.

Revenue from Qualcomm's handset unit, which makes chips for smartphones, fell 26% to $5.14 billion in the fiscal fourth quarter, dragging the chip segment's revenue down 8% to $9.02 billion. Analysts polled by Visible Alpha had expected handset revenue of $5.25 billion.

Global smartphone shipments fell 20% in the September quarter to a 14-year low, according to Counterpoint Research, as surging memory chip costs drove up device prices amid booming demand from AI data centers. Qualcomm Chief Executive Cristiano Amon told Reuters that sales of Android handsets had bottomed out and were ticking upward again.

The broader results were stronger than the handset line suggested. Adjusted sales in the fourth quarter fell 7% to $10.44 billion, beating estimates of $10.11 billion, while adjusted profit came in at $2.17 per share, compared with estimates of $2.16. Automotive revenue rose sharply, and the company said it expected $650 million in data-center sales in the fiscal first quarter, above analysts' expectations of $539.1 million.

For the current quarter, Qualcomm expects revenue of between $10.4 billion and $11.2 billion, the midpoint of which is above analysts' average estimate of $10.48 billion, according to data compiled by LSEG. Adjusted profit is expected to be between $2.15 and $2.35 per share, with the $2.25 midpoint below estimates of $2.27. Amon said the first-quarter forecast includes no further sales to Apple, and that Qualcomm expects revenue outside handsets to replace Apple entirely.