Thea Killengreen primarily works with transactions/M&A as well as general corporate law and insolvency. She also has extensive experience in commercial dispute resolution. Within the field of M&A, her work includes strategic advice in connection with transactions and restructuring as well as advice to companies in restructuring processes with financial and operational challenges. Assignments are related to every step in equity transactions, from assistance in connection with due diligence investigations, assessing deal structure, and negotiating transaction agreements, to the closing of transactions. Killengreen also advises Norwegian and international clients in connection with processes on the Oslo stock exchange.

Killengreen has a master's degree in law from the University of Bergen and King's College London. She wrote a master's thesis in International Financial Law at King's College London. The master's thesis was entitled «Implementation of MiFID II in Norway: Its influence and consequences for Norwegian legislation and the Norwegian financial market, together with the new provisions.