if the parties’ combined share of sales in any overlapping supply markets is less than 15% fin.

[Transl]

Filings on a Short Form require significantly less information than the standard Form CO. The proposed transaction would qualify for a Short Form notification if the parties’ combined share of sales in any overlapping supply markets (such as coal or power generation) is less than 15%, and if neither party has a share of sale in excess of 25% in any markets upstream or downstream of coal and power generation (such as control over power distribution lines, pipelines, or natural gas).

Речь идет об уведомлениях Комиссии ЕС о слиянии в рамках merger control.

[euromonik]

если совокупная доля продаж сторон на пересекающихся (перекрещивающихся) рынках продавца меньше, чем 15%

supply market - рынок продавца как экономический термин