AT&T Inc and media and entertainment group Time Warner Inc, which are seeking to merge despite US Justice Department opposition, extended the termination date for their deal to June 21, AT&T said in a filing on Friday.
The Justice Department sued in November to stop the $85 billion deal, and a trial is to begin on March 19.
Judge Richard Leon said during a hearing at the US District Court for the District of Columbia in early December that he would likely not have a decision by the deadline in the companies' merger agreement, but would rule in late April or May.
Under a previous agreement, either company could terminate the deal if it was not completed as of April 22.