Panasonic Corporation, which in partnership owns a battery factory with Tesla Inc., sold the entirety of its stake in the electric vehicle maker. The company had $729 million of Tesla shares by March last year but the stake had been decreased to zero by the end of this March, Panasonic disclosed in a filing on Friday. The filing didn’t give any sign of why Panasonic abandoned its interest. Tesla’s stock raised more than fivefold in the same 12-month period.

The Nikkei reported the news earlier, saying Panasonic will book several hundred billion yen in profit and will use the profits to pay its acquisition of artificial intelligence software developer Blue Yonder which is $7 billion.

Panasonic is Tesla’s oldest battery supplier and the duo has invested billions of dollars in a battery factory in Nevada. The partnership has been controversial at points, with Panasonic facing frequent and s public prods from Tesla Chief Executive Officer Elon Musk to increase the production of batteries. Shares of Panasonic rose to 4.8 per cent in Tokyo on Friday. Tesla closed 3.5 per cent higher in the US on Thursday. Its Nasdaq-traded stock touched a high of $883.09 in January.