The sale will make the Japanese firm a major shareholder with a 11 percent stake.
PAN has sent voting ballots to shareholders and asked for their submission by September 4.
If approved, the stake sale is likely to take place between quarters three and four this year.
According to PAN, the price of a share will be negotiated but not lower than VND55,000 ($2.4). This means the firm planned to raise at least VND817.3 billion ($35.09 million) from the private placement deal.
There will be a lock-up period of one year from the date of the deal within which Sojitz cannot sell the shares.
The stake sale - and more are likely - will help PAN acquire a strategic shareholder and have resources to acquire stakes in agricultural, materials, food and nutrition, packaged foods, and beverages companies.
Established in 1998 and rapidly expanding in recent years through M&A deals, PAN Group is a leading Vietnamese player in agriculture and food.
It had consolidated assets of over VND 7.6 trillion ($337.8 million) as of June 30 this year.
Its subsidiaries include leading companies like Vinaseed, PAN-SALADBOWL, Fimex, Bibica, Lafooco, AquatexBentre, 584 Nha Trang Seaproduct.
Its shareholders include NDH Invest, SSI, CSC Vietnam, The Asian Entrepreneur Legacy (TAEL) Partners, GIC, and PYN.
Sojitz Group has around 400 subsidiaries and affiliates in Japan and around the world, most of them in general trading.
The strategic deal with Sojitz was mentioned by PAN chairman Nguyen Duy Hung last April when he said the company needed funds to develop hi-tech products.
This year PAN targets a net profit of VND538 billion($23.9 million) on revenues of VND8.7 trillion ($366.6 million).
In the first half its net sales and consolidated profit both grew in double-digits to VND3.5 trillion ($155.5 million) and VND205 billion($9.1 million).
On August 21, each PAN share closed at VND58,700 ($2.6) on the Ho Chi Minh City stock exchange.