Panasonic sold its entire stake in key battery customer Tesla—worth an estimated $3.6 billion—last fiscal year, Nikkei Asia reported Friday.

The move gives Panasonic funds for new strategic investments, such as the $7.1 billion purchase of logistics and supply-chain firm Blue Yonder, the report noted. It's an indication Panasonic could wish to diversify its business away from the current battery boom.

The company has notified Tesla about the share sale, which was completed in March, and will continue supply the automaker with batteries, according to the report. A Panasonic executive told Nikkei Asia the company's business relationship won't change.

After signing its first supply contract with Tesla in 2009, Panasonic bought into the automaker in 2010. The two companies subsequently developed a close relationship, with Panasonic becoming Tesla's sole battery supplier and a partner in the automaker's Nevada "Gigafactory" battery plant.

Panasonic Li-Ion EV battery

Panasonic Li-Ion EV battery

However, the two companies may now be moving in different directions. Panasonic's EV battery boss earlier this year expressed some skepticism about Tesla's plan for a broad shift to the 4680 cell format. Tesla CEO Elon Musk has said these large-format cells will be key to the automaker's future product plans.

Panasonic also appears headed for joint development of some battery technologies with Toyota. Although Toyota is taking it slow, that could result in lucrative global contracts as Japan's largest automaker ramps up EV production.

Tesla meanwhile has turned to other battery suppliers, in addition to its own aspirations to ramp up large-scale production of cells. It turned to CATL for lithium iron phosphate (LFP) cells in China-built Model 3s, and has been reportedly planning to use LG NCMA cells in China-built Model Ys.

Panasonic and Tesla did renew their long-term battery supply commitment, however, and a serious boost in battery energy density remains due for the cells that Panasonic plans to keep supplying to the automaker.