President Donald Trump blocked Singapore chipmaker Broadcom from pursuing a hostile takeover of U.S. rival Qualcomm on national-security grounds.
The decision, announced late Monday, abruptly ends Broadcom's four-month $121 billion bid to buy Qualcomm, based in San Diego — a deal that would have been the largest ever completed in the technology industry.
Neither Broadcom nor Qualcomm immediately responded to requests for comment.
Broadcom faced challenges almost from the start of its quest. Qualcomm quickly spurned its unsolicited suitor and continued to resist even after Broadcom raised its original offer from $103 billion.
Broadcom's Singapore connections complicated matters, raising fears about a prominent U.S. chipmaker being owned by a foreign company.
Although its name isn't widely known outside the technology industry, Qualcomm is one of the world's leading makers of the processors that power many smartphones and other mobile devices. Qualcomm also owns patents on key pieces of mobile technology that Apple and other manufacturers rely upon in their products.
Trump decided to squelch Broadcom's bid on the recommendation of the Committee on Foreign Investment in the United States, which reviews foreign purchases of U.S. entities.
The decision didn't come as a surprise. Earlier this month, the committee branded the proposed deal a potential security risk that could hobble the U.S.'s ability to accelerate the speed of mobile networks to an ultra-fast standard known as "5G."
In an attempt to ease those worries, Broadcom last week pledged to make the U.S. a leader in the race to build 5G networks, saying it would create a $1.5 billion fund to support the effort if took control of Qualcomm.
Broadcom also tried to curry favor by moving its legal headquarters from Singapore to the U.S. The company's physical headquarters is already in San Jose, California — about 450 miles from Qualcomm's headquarters in San Diego.
Trump hosted Broadcom CEO Hock E. Tan in the White House last year when the executive announced the proposed move.