The move does not mean he will have a stake in the company, according to Goodhead Group chief executive David Holland, despite rumours to the contrary.
He claimed that Rosser, who resigned from Goodhead Group in 1993, is not looking to purchase the company, which is currently owned by multi-millionaire Sir John Madejski.
"Colin Rosser has been brought in to rebalance the board. He has huge experience and it will be good to have him on board as a non-executive director," Holland said.
In August of this year, Madejski said in a BBC Four documentary that he has too many business interests and that he has "got to start relinquishing some of them".