Shares in Cobham rose 1.2% today to 161.65p, close to the Advent bid price of 165p.
Cobham is a major supplier to top manufacturers such as Boeing, which makes the KC-46 aerial refuelling tanker using Cobham kit.
Advent has argued that it is not the type of investor that cuts jobs and asset strips, claiming it wants to invest and grow Cobham, not cut it.
The company also owns UK tech company Laird and has invested in it since taking it over in 2018.
Cobham is slowly on the mend after a disastrous period, including a string of profit warnings.
The chief executive and chairman both had to quit and shareholders’ confidence was seriously dented.
Lockwood has won plaudits for fixing the battered company and much of the sensitivity over price is from shareholders feeling they are not getting a full enough price to reflect the turnaround.
Advent is perhaps best known for making spectacular profits from its takeover of the payments processing company Worldpay, which it bought for £2 billion and floated five years later for £5 billion.
It also bought Brammer group off the London Stock Exchange and has since expanded it through acquisitions.