June 24 (Reuters) - State-owned Abu Dhabi National Oil Co, or ADNOC, has been pursuing a series of merger and acquisition deals with European companies, with an aim to diversify and develop its chemicals and renewable energy operations.

Here are the deals and talks ADNOC is involved in:

COVESTRO

German chemicals firm Covestro said on Monday it had given ADNOC access to its books and was stepping up talks based on an improved 11.7 billion euro ($12.55 billion) takeover offer, after more than a year of courtship by the Emirati company.

OMV

Austrian oil and gas company OMV has been in talks over a planned $30 billion merger between petrochemicals group Borealis - owned by OMV and ADNOC in a 75:25 split - and Abu Dhabi-listed Borouge, which is 54:36 owned by ADNOC and Borealis.

During its Capital Markets Day event in June, OMV's CEO Alfred Stern said the negotiations would continue and there was no deadline to conclude them.

In February, ADNOC closed the acquisition of a 24.9% stake in OMV, agreed in late 2022, increasing its holdings in both Borealis and Borouge. It did not disclose the ownership ratios.

FERTIGLOBE

ADNOC agreed in December to take over European chemical producer OCI's entire stake in ammonia and urea producer Fertiglobe for $3.62 billion, becoming its largest shareholder. ($1 = 0.9323 euros) (Reporting by Tristan Veyet, Isabel Demetz in Gdansk, editing by Milla Nissi)