Jan 30 (Reuters) - Semiconductor-testing equipment maker Teradyne forecast its first-quarter revenue below Wall Street estimates on Tuesday, hurt by lower demand for its chip-testing equipment.

Shares of the company fell around 6% in extended trading.

The company designs and develops technology to test chips and electronic equipment and sells robotic systems to customers in the manufacturing sector.

Teradyne's revenue has been declining year-on-year over the past few quarters as the chip-testing technology provider grapples with lower demand for its products as clients cut back on spending amid an uncertain economy.

"Looking into the new year, we expect low tester utilization will impact demand in the first half of the year" said Teradyne CEO Greg Smith.

Teradyne had flagged in November that the ongoing Israel-Hamas conflict was expected to have a negative impact on its future revenue and supply chain.

The company, which supplies equipment to chip designer Qualcomm and electronics firm Samsung, said it expects first-quarter revenue in the range of $540 million to $590 million compared with estimates of $625.1 million, according to LSEG data.

It also expects adjusted earnings per share for the first quarter in the range of 22 cents to 38 cents, compared with estimates of 53 cents.

Net revenue for the fourth quarter was $670.6 million, below analysts' expectations of $674.7 million.

(Reporting by Zaheer Kachwala and Tanya Jain in Bengaluru; Editing by Shilpi Majumdar and Krishna Chandra Eluri)