Adds analyst comments in paragraph 8

By Ateev Bhandari and Arasu Kannagi Basil

June 5 (Reuters) - Self-driving truck startup Plus Automation will go public in the United States through a $1.2 billion merger with special purpose acquisition company Churchill Capital Corp IX CCIX.O, the companies said on Thursday.

The merger, backed by veteran Wall Street dealmaker Michael Klein, will provide Plus $300 million in proceeds to fund the commercial launch of its autonomous trucks in 2027.

Commercialization of the self-driving space, widely seen as the future of transportation, has picked up pace in recent months as companies shift from bold promises to cautious progress.

Truck operators in the U.S., responsible for the majority of freight movement within the country, are increasingly looking to automate to reduce transportation and logistics costs amid driver shortages and heightened demand for expedited deliveries.

Deployment of self-driving technology is also expected to gain from less stringent regulations under the Trump administration, which plans to exempt certain vehicles from specific safety requirements and ease rules for reporting safety incidents.

In April, California proposed to allow testing of self-driving heavy-duty trucks and other large vehicles on state public roads.

The deal comes more than four years after Plus's previous attempt to go public through a $3.3 billion blank-check deal at the height of the SPAC frenzy, which was eventually canceled.

"IPO is an extremely expensive process and a lot of them don't want to go through the expense to pull the IPO in the last minute," said Yuriy Shterk, global head of alternatives at Clearwater Analytics, referring to the quick-to-list path that SPACs provide.

Plus, which counts Hyundai 005380.KS as a customer, is currently conducting public road testing in Texas and Sweden, with more customer fleet trials scheduled for fall 2025. Uber-backed UBER.N Aurora Innovation has also been testing self-driving trucks in Texas.

The deal is expected to close in the fourth quarter of 2025.

(Reporting by Arasu Kannagi Basil and Ateev Bhandari in Bengaluru; Editing by Vijay Kishore and Mohammed Safi Shamsi)

((ArasuKannagi.Basil@thomsonreuters.com;))