The EU policy on R&D agreements exempts low market share firms from antitrust concerns. However, limiting this exemption to low market shares may not be supported by existing theory. Introducing non-innovating firms into the framework shows that the market share criterion can hinder beneficial R&D cooperation agreements. Cooperation in concentrated industries may be desirable, while harmful in competitive ones. If R&D cooperation has anti-competitive effects in product markets, other tools may be more effective than market share criteria.