By Max A. Cherney and Stephen Nellis

(Reuters) -Intel Chief Executive Pat Gelsinger has stepped down less than four years after taking the helm of the company, handing control to two lieutenants as the faltering American chipmaking icon searches for a permanent replacement.

Gelsinger, who resigned on Dec. 1, left the company before the completion of an ambitious and costly four-year plan to restore the company's lead in making the fastest and smallest computer chips, a crown it lost to Taiwan Semiconductor Manufacturing Co, which makes chips for Intel rivals such as Nvidia.

Under Gelsinger's watch, Intel, which was founded in 1968 and for decades formed the bedrock of Silicon Valley's global dominance in chips, has withered to a market value more than 30 times smaller than Nvidia, the leader in artificial intelligence chips.

Gelsinger has assured both investors and U.S. officials, who are subsidizing Intel's turnaround, that his manufacturing plans remain on track. But the full results will not be known until next year, when the company aims to bring a flagship laptop chip back into its own factories.

Shares of the company rose 3%. The stock has lost more than half of its value this year, and it was replaced last month by Nvidia on the blue-chip Dow Jones Industrial Average index .

The company named Chief Financial Officer David Zinsner and senior executive Michelle Johnston Holthaus as interim co-chief executive officers while its board conducted a search for a new CEO. The moves come less than a week after U.S. officials gave $7.86 billion in subsidies to Intel.

The board has formed a search committee to appoint Gelsinger's successor.

"While we have made significant progress in regaining manufacturing competitiveness and building the capabilities to be a world-class foundry, we know that we have much more work to do at the company and are committed to restoring investor confidence," Frank Yeary, independent chair of the board, said in a release.

Intel's communications chief, Karen Kahn, has also left the company, according to two people with knowledge of the situation.

SPENDING SPREE

Gelsinger announced his turnaround plan in July 2021, when the company was already troubled by years of missteps in its manufacturing operations, and then embarked on a spending spree, starting construction on a $20 billion suite of new factories in Ohio and hiring a larger workforce - at 132,000 - than Intel had ever maintained even during its days as the biggest player in the chip business.

But the spending coincided with a post-pandemic collapse in the market for laptops and PCs, which in turn sank Intel's gross margins well below historical norms and depressed its stock price, sparking takeover interest in the company.