(Adds details of Petrocelli's role, share prices, background)
WASHINGTON, Nov 16 (Reuters) - AT&T Inc said it had hired media lawyer Daniel Petrocelli, whose clients have included U.S. President Donald Trump, to defend its acquisition of media and entertainment company Time Warner Inc if the government sues to block the deal.
Petrocelli, a partner at O'Melveny & Myers in Los Angeles, will be lead trial counsel for both companies if the case ends up before a judge, a spokesman for AT&T, the No. 2 U.S. wireless company, said on Thursday.
Petrocelli has represented Walt Disney Co and Time Warner in the past. Last year he defended Trump, then a presidential candidate, against fraud lawsuits involving real estate seminars known as Trump University.
Shares of AT&T were up 1.2 percent at $34.26 in midday trading, while Time Warner rose 0.4 percent to $87.75.
The Justice Department is expected to file an antitrust lawsuit as soon as this week to block the $85.4 billion AT&T deal.
The department has approached 18 state attorneys general to try to win their support for a lawsuit, a person briefed on the matter said on Wednesday.
As of Thursday, there were no indications that any states had signed on to a complaint, according to a person familiar with the matter.
AT&T, which is also a major pay-TV provider, and Time Warner have struggled to keep viewers who have flocked to online services like Netflix Inc and Amazon.com Inc's Prime Video.
AT&T wants to buy Time Warner so it can bundle mobile service with video entertainment and take online advertising from Facebook Inc and Alphabet Inc. (Reporting by Diane Bartz; Editing by Paul Simao and Lisa Von Ahn)