Private equity firms Silver Lake Management LLC and Thoma Bravo LLC reduced their exposure to SolarWinds Corp. days before a hack warning related to one of the software company's products was issued, the Financial Times (London) reported.

The technology-focused firms sold a 5%, or $315 million, stake in the business to the Canada Public Pension Plan Investment Board. The $21.97 per share private placement closed on Dec. 7, the report said, citing a securities filing.

The private equity firms held a combined share of around 75% in SolarWinds as of the end of September, the report said, citing regulatory filings. Three executives from each firm sit on the software company's board.

The U.S. government issued an emergency warning on Dec. 13 about an apparent cyber espionage campaign centered on the Orion software, which is used by federal agencies and most Fortune 500 companies.

SolarWinds' share price fell as a consequence, and was priced at $18.52 on Dec. 16, the report said.

In a joint statement, the private equity firms said they were unaware of the possible cyber attack at SolarWinds before entering into the private placement. CPPIB declined to comment.