Ajax are in 15th place in the 18-team Eredivisie table and have not won a match since the opening weekend, despite spending over 100 million euros on new players in the close season.

Ajax finished third last season and failed to qualify for the Champions League for the first time in 13 seasons.

Van Gaal, 72, won three league championships and the 1995 Champions League as head coach of the Amsterdam side between 1991 and 1997.

"I want to help Ajax, I'd like to bring in my football knowledge," Van Gaal said in a statement. "We must find the way up again."

Last week, Ajax fired their director of football Sven Mislintat, who had only been appointed in May, in a bid to quell unrest in and around the club due to their disappointing results.

Mislintat's dismissal came hours after their home game against Feyenoord had to be abandoned when fans started rioting as Ajax went 3-0 down.

Ajax ultimately lost the match 4-0 when the remainder was played last Wednesday.

Ajax's away match against RKC Waalwijk last Saturday was also abandoned a few minutes from time after RKC goalkeeper Etienne Vaessen was knocked out in a clash with an opposing player - with Ajax leading 3-2.

During a 30-year career as a coach, Van Gaal also managed Barcelona, Bayern Munich and Manchester United and finished third with the Dutch national team at the 2014 World Cup.