Soaring oil prices are hurting shares of once high-flying aviation suppliers, with engine maker GE Aerospace suffering the brunt of the selloff.

Its shares were down about 3% midday at $308.50, extending a nearly weeklong slump for the manufacturer. Commercial and military suppliers Honeywell Aerospace and RTX have suffered more modest share declines so far this week.

U.S. crude oil prices leapt above $100 a barrel this month, a level that threatens to erode demand for air travel that proved relatively resilient over the summer. Melius Research analyst Scott Mikus downgraded his GE and Honeywell recommendations Monday to hold from buy, saying their lucrative "aftermarket" demand could take a hit.

"Jet fuel costs have roughly doubled since the start of the year, and airlines are retiring older aircraft and engines as Boeing and Airbus steadily boost new aircraft deliveries," he said. "A replacement cycle is underway. That isn't good for aftermarket companies that derive the majority of their profits from spare parts and maintenance services."

GE Aerospace's stock was already under pressure this month after it offered $11.75 billion to snap up supplier Consolidated Precision Products. Wall Street analysts said the purchase was an expensive way to secure a business expected to generate about $2 billion of revenue next year, though it could help GE ensure a steady supply of advanced castings needed to make its engines more efficient and durable.