Larry Ellison, the founder of software giant Oracle Corp. (ORCL) , disclosed he has a $1 billion stake in electric vehicle company Tesla Inc. (TSLA) .

The disclosure came in a filing with the Securities and Exchange Commission.

Ellison, the current executive chairman and chief technology officer of Oracle, was added to Tesla's board last month, as was Kathleen Wilson-Thompson, the global head of human resources at Walgreens Boots Alliance Inc. (WBA) .

The board additions were part of a settlement reached earlier in 2018 between Tesla CEO Elon Musk and the SEC that allowed Musk to remain CEO of the company he founded but forced him to step down as chairman. 

"In conducting a widespread search over the last few months, we sought to add independent directors with skills that would complement the current board's experience," Tesla said. "In Larry and Kathleen, we have added a preeminent entrepreneur and a human resources leader, both of whom have a passion for sustainable energy."

Ellison, reportedly a long-time friend of Musk, indirectly owns 3 million Tesla shares through the Lawrence J. Ellison Revocable Trust, according to the filing. The 1.75% stake makes him the second-largest disclosed individual shareholder after Musk, who owns about a fifth of the company, according to data compiled by Bloomberg

Tesla shares rose 2.1% on Tuesday.