Walter Smith last night called for unity among the directors at Rangers after he was appointed non-executive chairman of the Ibrox club.

The former Rangers manager – whose two spells in charge of the first team brought 10 league titles and a UEFA Cup final appearance in 2008 – was confirmed in his new role after receiving the "unanimous" approval of the club's board.

Smith replaces Malcolm Murray in the post after the businessman agreed to step down following weeks of turmoil in the Ibrox boardroom which included attempts to oust Murray from the club. However, in a statement to the Stock Exchange, Rangers directors expressed confidence that Smith will "bring stability, experience and a wealth of knowledge to the club".

Despite reports suggesting at one stage that the former Scotland manager would step down from his position as director at the club as a result of boardroom disharmony, Smith can be considered to be the right choice as Murray's successor. His authority and presence should help to unite an increasingly fractious board, while Rangers are also still contending with claim and counter-claim as former owner Craig Whyte and former Rangers chief executive Charles Green have argued over the negotiations that led to Green's acquisition of Rangers' business and assets last summer.

Indeed, Smith was confirmed in his new role just hours after an independent investigation commissioned by the Rangers non-executive directors found no evidence that Whyte had invested in the current Ibrox set-up.

It was with reference to such enduring disquiet that Smith gave his first address as chairman last night. "Although I have been on the board for some months this will be another departure for me but there are enough directors around to make sure we will make the kind of progress necessary and which our fans want," he said.

"Unity among the directors is vital. We must all be on the same page as often as possible. We won't always agree but Rangers, this club and our fans must always come first.

"It is a great honour to be asked to take up this position and it goes without saying that I feel proud as well as humble. However, no one should believe that I see my role as a passive one. That hasn't been my way in the past and it won't be my way in the future."

The former Rangers manager also paid tribute to Murray – "Malcolm stepped forward at a time when the club needed direction" – while Craig Mather, Rangers' acting chief executive, welcomed Smith's appointment. "The board believes the change will help drive the club forward and we could not have a better man at the helm," he said.

The necessity for Rangers will now be to move on, although Murray still offered a brief statement after he stepped down. "Walter has my support and I believe he can bring stability and focus to the club as we look to the future," he said.