Schalke and Russian sponsor Gazprom have prolonged their partnership until 2022 in a deal reported to be worth up to €150 million.
Gazprom's sponsorship of Schalke began in 2007 and has proved controversial for the Bundesliga club due to the gas company's connection to Russian President Vladimir Putin.
Schalke chief Clemens Tonnies has always maintained that they have been happy with the partnership, though, and a statement on the club's official website on Saturday confirmed that an agreement to extend the deal was reached at the end of last month.
Tonnies, Schalke's chairman of the board of directors, said: "I'm really happy about continuing our collaboration until 2022. We've worked together closely for years now and this new contract will only expand this partnership."
- FC Schalke 04 (@s04_en) May 7, 2016
Tonnies, who has made his fortune in the German meat industry, has business ties with the Kremlin and has in the past spoken about his friendship with Putin.
The official announcement said Tonnies' "good personal relationship" with Gazprom chairman Alexej Miller had "provided a positive impact on the already constructive talks."
Bild reported that the deal is worth up to €150m, and the club's marketing director Alexander Jobst said: "With this long-term contract, Gazprom will have a large contribution to FC Schalke 04's financial stability."
The news of the agreement was made prior to Schalke's final home match of the season on Saturday but brought a negative reaction from a number of fans, with Tonnies, who is currently campaigning for his re-election at the member's meeting on June 26, the subject of whistles.