Rolls-Royce, which makes engines for the Boeing 787 and Airbus 350, was beginning to see positive results from a four-year turnaround process earlier this year when the coronavirus pandemic struck, halting air travel and wreaking new havoc on its finances.
ValueAct, which invested in the company in 2015 at the height of its turmoil when it issued multiple profit warnings, is believed to have sold its remaining 4.5% Rolls stake in April, the source said.
Rolls has had a difficult time during the pandemic. It said in July it is looking at options to bolster its balance sheet after burning through 3 billion pounds ($3.9 billion) in the first half of the year as planes stopped flying, cutting the revenues it receives from flying-hours.
Reuters has reported that Rolls-Royce is planning a share issue to raise up to 1.5 billion pounds.
Shares in Rolls-Royce fell 2.8% in morning trading on Friday to 246 pence, putting the stock at its lowest level for 11 years, after a report that ValueAct had sold out.
ValueAct was not immediately available for comment on the stake sale, initially reported by the Financial Times. No regulatory filings are required when a stake is already under 5%. ValueAct had previously owned a 9.48% stake in Rolls.
Rolls-Royce declined to comment.
By Sarah Young