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