Amazon.com Inc.’s top cloud-computing executive has officially denied that Amazon Web Services plans to start selling network switches to other businesses, after a report last week claiming that move was in the works damaged stocks of Cisco Systems Inc. and other major networking companies.

“Cisco and AWS have a longstanding customer and partner relationship, and during a recent call between Cisco CEO Chuck Robbins and AWS CEO Andy Jassy, Andy confirmed that AWS is not actively building a commercial network switch,” a Cisco Systems Inc. spokesman told MarketWatch on Wednesday.

An AWS spokeswoman confirmed the statement Wednesday, but declined to go into more detail.

The Information reported Friday that Amazon AMZN, +0.66% was considering selling its own network switches with built-in connections to its Amazon Web Services cloud-computing offerings. The report said Amazon’s generic networking equipment would be based on open-source software and sourced from “white box” manufacturers, which would likely make the product much cheaper than offerings from the larger networking companies.

The report was especially damaging for Cisco CSCO, -1.12% , the market leader in switch sales that has already struggled to grow revenue from switches while being challenged by white-box manufacturers from the low end and Arista Networks Inc. ANET, -0.01% in high-quality gear. Cisco stock declined 3.1% since the article appeared Friday through the close of Wednesday’s session, while Arista fell 1.3% and Juniper Networks Inc. JNPR, -1.02% has dropped 0.9%. The S&P 500 index SPX, +0.29% has gained about 0.1% in that time.

After MarketWatch first reported the denial, Cisco stock jumped 3% in after-hours trading, while Arista shares rose about 1.4% and Juniper stock gained about 1.8%. Amazon stock was calm in late trading.

Amazon would not comment on whether it is creating its own networking equipment, just that it did not plan to sell such equipment to other businesses. Many large tech companies are fashioning their own equipment for data centers, and Facebook Inc. FB, +0.20% has distributed blueprints for building networks out of white-box equipment.

“Google GOOGL, +0.95% GOOG, +0.92% , Facebook, LinkedIn and a few others have created unique networking equipment—with merchant components—for the their data centers, because their data centers are their competitive differentiators,” Forrester analyst Andre Kindness noted in discussing the potential move with MarketWatch.

Opinion was split on whether Amazon’s move would have truly harmed Cisco. While many analysts were concerned that the move could endanger an important Cisco business that has already struggled to show growth, others pointed out that previous moves toward white-box equipment have not done much damage because of the software and services support that larger networking companies offer with their equipment.

“Other hyperscale vendors, namely Facebook, have made their whitebox reference design available for a couple of years, both with little to no general enterprise adoption,” Morgan Stanley analysts wrote in a note responding to the report. “The reason that impact has been minimal has tended to be that the ease of management is far more critical than the cost of underlying equipment (i.e. Cisco estimates that companies spend $15 in operating costs over the course of five years for each dollar spent on networking equipment).”

Amazon, however, has proved its ability to break into new sectors and damage legacy leaders, just as its core e-commerce business did to brick-and-mortar retail giants, at least in terms of market valuation. The company’s acquisition of Whole Foods Markets Inc. sent investors scurrying from other grocery stocks, and ambitions to break into pharmaceutical sales and health care have caused unrest in those sectors as well.