Washington,The US Federal Trade Commission is seeking a preliminary injunction against Facebook over its anti-competitive market practices.

According to a report in The Wall Street Journal, the FTC action "would focus on Facebook's policies concerning it how it integrates its apps or allows them to work with potential rivals".

Facebook's key products include Instagram, Messenger and WhatsApp.

After the report was out on Thursday, Facebook shares fell 2.7 per cent at the end of the trading day.

Facebook is aiming to integrate all its apps and encrypt them end-to-end, which is a worry for law enforcement officials including Attorney General William Barr.

It argues that the move would give users more privacy.

The US House Anti-Trust Committee has also opened probes into Facebook and other tech giants to determine if they prevent competition and hurt consumers.

Nearly 50 attorneys general have officially joined the investigation into Facebook for its anti-competitive market practices.

They are "all concerned that Facebook may have put consumer data at risk, reduced the quality of consumers' choices, and increased the price of advertising".

"We will use every investigative tool at our disposal to determine whether Facebook's actions stifled competition and put users at risk," New York Attorney General Letitia James said in a statement recently.

Facebook had earlier said it will work "constructively" with the attorneys general and engage with policy makers in a discussion about the competitive environment.

"Social media is a critical part of doing business in today's economy. Any effort by Facebook to unlawfully stifle competition could cause wide-ranging harm to smaller companies, restrict consumer choice, and increase costs for all," said Connecticut Attorney General William Tong.

"The District of Columbia has joined this investigation to ensure Facebook is giving a fair shake to district residents and the American people. No company gets a pass if it throttles competitors and exploits consumers," said District of Columbia Attorney General Karl A. Racine.

US trade body seeks preliminary injunction against Facebook