Traditionally, the innovation process has been of a closed nature because research or development projects are generated inside the company and brought to the market by a company. However, Chesbrough (2003) formulated the open innovation paradigm, assuming that companies can and should use external and internal ideas as well as external and internal market paths in search of new opportunities for their development. Openness to innovation requires cooperation with other market players, therefore some kind of partnership is necessary to co-create value with various stakeholders. The partners share their knowledge and experience as well as the benefits of jointly conducted innovative projects. Managing this type of partnership is now considered one of the key competences of the organization. However, the issue of managing the innovation ecosystem as the most mature form of open innovation has been relatively poorly researched. We do not know much about what organizational and legal solutions are adopted by companies in partnerships for the development of innovation, what a model of cooperation could look like or how to manage such a partnership. How far should we formalize these processes? While searching for answers to these questions, the author decided to conduct empirical research in 2019 among the consortium members of Group Azoty Puławy (nitrogen fertilizers production), based on an in-depth, partially structured interview, supported by an analysis of several selected innovation ecosystems of global chemical groups (BASF, MONSANTO, SOLVAY and YARA). Group Azoty Puławy is part of Group Azoty, the second largest producer of mineral fertilizers in Europe. In 2019, Group Azoty Puławy generated revenues of EUR 845.4 million and profit of EUR 70.7 million. The results for the first nine months of 2020 were EUR 533.7 million and EUR 37.2 million, respectively (Group Azoty Puławy interim reports 2020; 2021). The subject of the research was a consortium established in 2011 by Group Azoty Puławy in order to implement joint innovation projects. In the period between 2011 and 2016, consortium members submitted 22 initiatives, 6 of which were completed by 2016. After five years of operation, the consortium consisted of 12 members, including 5 representatives of scientific institutions, 3 producers of agricultural products and 4 organizations representing agricultural entrepreneurs. The purpose of the research was to assess the degree of openness of project participants to cooperation during the construction phase and the management phase of the consortium. The research of innovation consortium of the Group Azoty Puławy shows the following: During the construction phase, the members of the consortium were open to the accession of new partners, however selectively, i.e. according to the leader’s instructions. The selection of partners was complementary and concerned entities serving the same market segment as leaders. During the management phase of the consortium, the solution that gave the leader the greatest power had the largest number of followers. Most of the respondents were in favour of a formalized cooperation strategy, i.e. the one based on standardizing relations between partners. The respondents were open to both formal (specific, contractual) and informal (relational) mechanisms in building and managing a partnership.