BERLIN, June 24 (Reuters) - World swimming federation FINA on Thursday extended an invitation to independent pro series the International Swimming League (ISL) to work together for the benefit of the sport. Newly elected FINA President Husain Al Musallam said he was committed to reforming the federation after this month replacing Julio Maglione, who had been in charge for 12 years and whose administration had opposed the creation of the ISL. The ISL was founded in 2017 and FINA at the time had urged national federations to refuse to cooperate with it, threatening to ban swimmers who took part in independently organised events. But after pressure from top swimmers, FINA cleared athletes to participate in non-FINA sanctioned competitions, including the inaugural ISL season in 2019. "For me as president of FINA, my door is open for ISL or any other commercial operation," Husain Al Musallam said in a conference call. "We will work with ISL if ISL would like to work with FINA." "If any entity would like to play a positive role to help the movement I will be the first one to congratulate them and shake their hand," he said. FINA"s revenues took a big hit in the past year and some budgets had been cut, he said, without providing financial details. The club-based ISL series features many of the world"s top swimmers and held its second season finals behind closed doors in Budapest last November, with a number of short-course world records broken. It has since announced season three would start in the Italian city of Naples in August. Swimming is a top Olympic sport and will have the most medal events at the Tokyo Olympics next month with 49, one more than athletics, another major Olympic sport.