New deal for Koeman
Koeman, who finished his playing career with the Rotterdam side, is in his first season as Feyenoord coach, and his side sit in fifth place in the Eredivisie, seven points from the summit after 17 games.
"We are doing good work and giving Feyenoord something to build on. The head coach is the key figure and continuity is important."
Van Geel revealed that the 48-year-old former Benfica, PSV Eindhoven and Valencia boss would receive a "significant upgrade" to his contract, but did not reveal any figures.
"We have definitely remained within our financial limits," he said. "We have a deal everyone can be happy with."
Koeman added: "I'm really enjoying myself at Feyenoord and am glad we have found agreement. We see a lot of opportunities to grow with this talented group."