* Sony considers investing 50 bln yen in Olympus-paper
* Sony to be Olympus' top shareholder-paper
* Olympus spokesman says deal not decided yet (Adds Olympus comment, background)
June 22 (Reuters) - Olympus Corp is in final talks with Sony Corp to get a roughly 50 billion yen ($622.86 million) capital injection in return for a stake, the Nikkei business daily reported on Friday, as the Japanese camera and medical equipment maker looks to rebuild from a huge accounting scandal.
Olympus, which posted its first annual loss in three years, is facing increasing pressure for a capital-tie up with another company, President Hiroyuki Sasa told Reuters on Wednesday.
After the deal, Sony will become Olympus' top shareholder with a more than 10 percent stake, the Nikkei said.
Sasa has said that he wants to boost the firm's shareholders' equity to 10 percent of its total assets as soon as possible, from 4.6 percent as of end-March. To do so, the firm will need to secure some 50 billion yen in fresh capital.
Analysts consider a 20 percent shareholders' equity ratio as indicative of financial stability for a company.
The two companies aim to reach an agreement next month and would join forces in medical equipment and other areas, the Nikkei said.
"This is not something that we have announced. It has not been decided yet," Tsuyoshi Oshima, an Olympus spokesman, said when asked about the report.
The negotiations with Sony, which vied with Panasonic Corp , Fujifilm Holdings Corp and Terumo Corp for the tie-up, may still fall through, the daily said.
Media reports have said that Panasonic would invest in Olympus, but Panasonic President Fumio Ohtsubo told Reuters earlier in June that he had no plan to do so. Panasonic posted a record net loss in the year ended March 31.
Sony also posted a record net loss of about $5.7 billion during the same period.
$1 = 80.2750 Japanese yen Reporting by Shubham Singhal in Bangalore and Yoko Kubota in Tokyo; Editing by Supriya Kurane and Muralikumar Anantharaman