Marek is an attorney-at-law, member of the Regional Chamber of Attorneys in Warsaw, founder and managing partner of Warsaw-based Polish independent law firm M.Furtek i Wspólnicy, vice president of the Arbitration Council of the Court of Arbitration at the Polish Chamber of Commerce in Warsaw, arbitrator for the Court of Arbitration at the Polish Chamber of Commerce in Warsaw, member of the National Council for Alternative Dispute Resolution in the Ministry of Justice, and member of the supervisory board of the Millennium Bank SA.
Since 1987 he has been a partner with various law firms. He is a legal adviser specialising in civil proceedings and arbitration, corporate law, commercial law, financial institutions and instruments. Until 1996, he was a member of the research staff of the Faculty of Law and Administration at the University of Warsaw (Civil Law Department). He is the author of many publications on civil and commercial law.
Marek has presided over or served as a member of arbitration panels in the Court of Arbitration at the Polish Chamber of Commerce in Warsaw, the ICC International Court of Arbitration, bilateral investment treaties arbitration and ad hoc arbitration courts in over 110 national and international disputes, advised as counsel in many arbitration and litigation proceedings.