By Elizabeth Koh

SEOUL--The West's fight with China about 5G network equipment has handed an opportunity to South Korea's Samsung Electronics Co.

The U.S. and U.K. have barred from their 5G networks China's Huawei Technologies Co., the industry's largest player. Other European countries are weighing whether to follow suit. In response, Beijing is considering blocking two European suppliers and the industry's next largest manufacturers, Nokia Corp. and Ericsson AB, from sending their China-made product elsewhere, The Wall Street Journal reported last week.

The geopolitical squabbling gives Samsung, the industry's No. 4 player, a major chance to muscle into a telecom-equipment market it considers a pillar for future growth. Though deep-pocketed, Samsung has been a fringe networks player for decades, mostly servicing its home market. But with stagnating sales from its former cash cows in smartphones and televisions, Samsung has bet billions of dollars that telecom operators will prefer a supplier who sells both the network equipment and all the consumer products that connect to it.

Samsung also manufactures its network gear entirely in South Korea, lending it cover from the tit-for-tat restrictions that its main competitors lack.

Even before the U.K. reversed course this month on its approach to Huawei, Samsung already had made some inroads. In the overall network-gear market, Samsung's share of sales of prior-generation equipment represents just a few percentage points. In the 5G realm, the South Korean firm controls roughly a seventh of the market where Huawei enjoys more than twice that, according to market research firm Dell'Oro Group.

Samsung's 5G sales could improve in the coming months, industry analysts say. It has dialed up its 5G marketing efforts, leaning on its end-to-end offerings in pitches to carriers and focusing on developing a future 6G service rather than the 2G or 3G coverage still needed in older markets. It has signed four new deals to provide 5G network gear in the past eight months, including in Canada and New Zealand.

The company rolled out a "6G Vision" white paper this month, touting technology like holograms that would be a digital twin of one's physical self. The technology is at best a decade away, but the messaging linked the future to today's reality, warning the transition to 6G will require even tighter cybersecurity protections.

In recent weeks, the company has been in discussions with some European operators about providing network equipment, particularly for 5G. Samsung executive vice president Kim Woo-june told a British parliamentary committee this month that the company could definitely build a 5G network in the U.K. if the opportunity arose, though he denied basing Samsung's strategy on what he called political winds.

"Wherever there's an opportunity, we'll go there with our products," Mr. Kim said.

The Chinese Foreign Ministry denied Beijing is weighing retaliation against the restrictions on Huawei. But Nokia and Ericsson employ thousands in their Chinese manufacturing plants, and China, which has taken the lead in the early 5G rollout, has been allocating a greater share of its 5G contracts to domestic vendors: If global tensions escalate, Samsung is the most likely main player to reap the benefits of not being caught in the crossfire. The Seoul government is on relatively good terms with Washington and Beijing. Samsung's de facto leader, Lee Jae-yong, in May was one of the first foreign business leaders to visit China after the pandemic took root.

But gaining more ground in the network infrastructure market will be a steep climb. The company had set a target back in 2018 to grab 20% of 5G market share by next year, still a sizable leap from its roughly 13% market-share standing today. But it was a goal that had appeared even more lofty not long ago. In late 2018, Samsung replaced its 5G-equipment head amid a stagnation in sales.

Samsung also has invested deeply in research to stake out more ground in the 5G space and owns the largest number of patents granted in the U.S., Europe or the Patent Cooperation Treaty, according to a January report by the Technical University of Berlin and a German research firm.

Operators overwhelmingly favor staying with incumbent vendors, unless there are major problems or the government steps in, said Stefan Pongratz, an analyst at Dell'Oro. More-established vendors have the benefit of covering legacy technologies as well as offering lower costs because their older equipment is compatible with their next-generation networks.

"Breaking that vendor lock-in allows some leveling of the playing field, " he said. "We should not be under the impression that that's all it takes."

Samsung has admitted Huawei beats it on cost: Mr. Kim, the networks executive, said at the British committee's July hearing that its Chinese competitor offers bids at prices unviable for Samsung and its partners.

It is also unclear if the company might hit a ceiling in Europe, where the geopolitical uncertainty opens up the most opportunity. Nokia and Ericsson, headquartered in Finland and Sweden respectively, retain significant home-turf advantage. Samsung, on the other hand, has made most of its deals so far in North America and other parts of the Asia-Pacific region.

Capturing just a few billion dollars in extra revenue in the networks market from those regions may also not move the needle significantly, compared with the hundreds of billions of dollars the company brings in across the entire enterprise, which includes semiconductors and consumer electronics, said Nam Hyung Kim, an analyst with Arete Research Services.

Still, growing the company's networks division would improve margins for Samsung's mobile business, which has seen profits from its signature smartphones falter. It also bolsters relationships with the carriers who are major sellers of Samsung's handsets. The networks business accounts for about 5% of the mobile division's revenue, but analysts estimate that ramped-up carrier spending in 2021 could double that figure or more.

Write to Elizabeth Koh at Elizabeth.Koh@wsj.com