Mallorca are in the process of going into voluntary administration in a bid to sort out their finances, lumbered by debts of up to 85 million euros.
"We are taking up this option to buy," Serra Ferrer was quoted as saying on the club website.
"The first thing to do is to thank the people who have thought similarly about trying to make Mallorca viable in sporting, economic and social terms."
Serra Ferrer's group will take over the shareholding of Mateu Alemany, who has been trying to find investors since former president Vicenc Grande's real estate company filed for insolvency in 2008.
Spanish daily El Mundo quoted sources, who said the group had paid around two million euros.
Looking ahead, one of Serra Ferrer's first moves will be to appoint a coach for next season with Dane Michael Laudrup being linked with the post vacated by Gregorio Manzano.
Against an unstable background including delayed payments to players, Mallorca were one of La Liga's surprise packages last season.
They only missed out on a place in the Champions League qualifying round on the final day of the campaign in May, ending fifth in the standings to earn a shot at next season's Europa League.
Serra Ferrer, 57, was born in Mallorca and spent the first ten years of his coaching career with the club before spells with Barcelona, AEK Athens and Real Betis, with whom he won the King's Cup in 2005.
