Sources, however, have said that PwC will give an "adverse opinion" on Toshiba's internal controls in an annual report due to be filed later on Thursday.
Toshiba was still in talks with various partners on the memorychip sales, Tsunakawa said, but declined to comment in detail on why the agreement was being delayed.
That would normally trigger a delisting from the Tokyo Stock Exchange.
Toshiba on Thursday met a looming deadline to report its long-delayed financial results, saying it lost around $8.8 billion in the last fiscal year over its hard-hit U.S. nuclear unit Westinghouse Electric.
But a spokeswoman at the TSE said that partial approval from an auditor does not eliminate the possibility of Toshiba's delisting.
There had been growing worries that Toshiba might not make Thursday's deadline to supply financial statements for the year ending March as it had been at odds with auditors over multi-billion-dollar losses at Westinghouse.
Following PwC's sign-off, the Tokyo Stock Exchange is now reviewing Toshiba's governance to decide whether the firm can stay listed.
What have the auditors said?
In June, Toshiba picked the consortium of state-backed Innovation Network Corp of Japan, the state-owned Development Bank of Japan and USA fund Bain Capital as its preferred bidder for its chip business.
The company needs to sell its prized chip business to cover its hefty U.S. losses. According to a Japanese securities filing, another USA hedge fund, King Street Capital Management, started buying Toshiba shares in June and now owns 5.81% of the company.
Toshiba still needs to get itself out of a negative net worth to avoid being delisted. The company seeks to sell its very big chip-making branch to the highest bidder, and has recently opened up negotiations with electronics titans Foxconn and Western Digital after previous talks with a Japanese-led consortium of buyers. PwC took over as Toshiba's auditor in June past year. "I can't imagine that anybody is going to pay real money for these assets until the legal situation has been made clear", Givens said, warning that the sale process would likely be paralyzed indefinitely as a result.