Private equity firm Veritas Capital has made an offer to buy BlackBerry, according to a person familiar with the matter, months after the Canadian technology company began a strategic review.

US-listed shares of BlackBerry, which earlier rose about 17% on the news, closed at US$5.23, giving the company a market capitalisation of $3.1-billion.

Details of the offer could not be determined. Veritas and BlackBerry did not immediately respond to requests for comment.

Veritas has made an offer for the entire company, the source said, adding that BlackBerry is also in talks with other potential buyers.

BlackBerry had said in May it would consider strategic options for its portfolio of businesses that could include the possible separation of one or more of its businesses.

Founded in 1984, the company currently makes software for cars and cybersecurity. It became popular for its ubiquitous business smartphones, toted by executives, politicians and legions of fans in the early 2000s.

It pulled the plug on its smartphones business last year and has since been trying to sell its legacy patents related to its mobile devices.

BlackBerry: phones to software

In May, BlackBerry said it will continue with the previously announced sale of the patents related to its mobile devices to Malikie Innovations for up to $900-million. A prior deal to sell those patents to Catapult IP Innovations for $600-million fell through as it took longer than usual to close.

In 2016, BlackBerry said it would no longer manufacture its classic smartphones. Since then, the firm has been attempting to remake itself as a provider of high-end software.

Read: BlackBerry movie review: a roller coaster tale of hubris

BlackBerry operates two primary businesses, one focused on cybersecurity software, while the other makes internet-of-things products. Veritas Capital is a technology investor that primarily buys and invests in companies that provide government-focused tools and services.