Keysight Technologies has thrown a $200 million wrench into rival Viavi Solution’s attempt to acquire Spirent Communications, highlighting the high-stakes game being played out in the automated network and equipment testing market.

California-based Keysight is offering to acquire London-based Spirent for nearly $1.5 billion, an amount that is an 85% premium over where Spirent’s stock was trading less than a month ago. It’s also a 15% premium – or roughly $200 million more in total value – than Viavi’s offer earlier this month.

Keysight’s offer garnered support from Spirent’s board of directors, though that same board also threw its support behind Viavi’s now not-supported offer, and said as much in a statement.

“The Spirent directors consider that the acquisition represents a superior proposition for Spirent shareholders relative to the Viavi offer,” Spirent and Keysight noted in a filing. “Accordingly, the Spirent directors have unanimously withdrawn their recommendation of the Viavi offer and intend to adjourn the Viavi offer shareholder meetings.”

Keysight in its offer highlighted Spirent’s work with high-performance test, assurance and automation platforms, and that the combined entity will have a strong presence in the aerospace, defense, automotive and communications space. Spirent is also focused on automated test and assurance systems for cellular networks, SD-WAN, cloud and positioning systems for autonomous vehicles.

“With the Spirent Group’s offerings, Keysight believes that it will be able to access new serviceable available market opportunities of up to $1.5 billion,” Keysight notes in its offer.

Arizona-based Viavi made its offer for Spirent earlier this month. That proposal came the same day Spirent released its most recent financial results, which included a near 22% drop in year-over-year revenues. Spirent related the plunge to an increasingly challenging market, with a specific mention of the telecommunications space.

Viavi’s offer was enough for Spirent’s management at that time, which stated the deal “provides a compelling opportunity for Spirent shareholders to accelerate and de-risk the potential future value creation, and realize an immediate and certain cash exit for their investment at a significant premium to the prevailing share price.”

Viavi in a statement noted that its offer remains superior operationally to Keysight's higher valuation and that end-users would be better served by a Viavi acquisition.

“Viavi believes that its acquisition represents certain value and notes its limited business overlap with Spirent relative to Keysight,” the firm stated. “Viavi believes that the proposed combination of Keysight and Spirent would further entrench Keysight’s leading position in many product segments, which would limit customer choice.”

The bidding war highlights the growing importance of overall test and measurement functions across industry verticals, with a big focus on open radio access network (RAN) deployments in the telecommunications space.

Keysight and Viavi have often been included together in various telecommunication industry consortiums as key automated testing providers.

This includes the recently founded Acceleration of Compatibility and Commercialization for Open RAN Deployments (ACCoRD) project funded from the Department of Commerce’s National Telecommunications and Information Administration (NTIA) and its Public Wireless Supply Chain Innovation Fund and led by telecom industry heavyweights like AT&T and Verizon. The work will focus on establishing testing protocols for network performance, interoperability, security and research into new open RAN testing methods.

“Evaluating how different products integrate with one another is a crucial part of facilitating the more diverse vendor ecosystem that many in the industry and government envision,” Robert Soni, VP of RAN technology at AT&T, wrote in a blog post on the project. “Operators need to have confidence that different vendors’ products will work together at scale before adding them to their network. … The best way to assess integration across the industry is to go big – which is why AT&T and Verizon came together to assemble a broad consortium that includes not only other major network operators like Jio and DoCoMo but also a wide range of vendors.”

Spirent has also been singled out by the Telecom Infra Project (TIP) for its private 5G blueprint efforts and by MEF for its SD-WAN certification process.

UPDATED: This story has been updated with a statement from Viavi.