Shareholders of Delta ( DAL) and Northwest ( NWA) meet Thursday and are expected to overwhelmingly back the deal combining the two airlines, the Associated Press reports. The combined company would be the world's biggest carrier. Four shareholder advisory firms have recommended votes in favor of the combination. A union that represents 12,500 Northwest ground workers opposes the deal. Majority votes are needed for the proposals to pass. An OK from shareholders leaves U.S. regulatory approval and a pending federal lawsuit seeking to block the deal as the only remaining hurdles, according to the AP. Delta hopes to close the deal by the end of the year. Delta's acquisition of Northwest is valued at about $2.8 billion, roughly $800 million less than when the deal was announced in April, the AP reports.