WASHINGTON: US lawmakers unveiled sweeping antitrust measures Friday aimed at tempering the dominance of Big Tech firms including Apple and Facebook, in what may be the most ambitious effort in decades to break corporate monopolies.

A bipartisan group of House members introduced five separate bills that propose changes so comprehensive they could reshape the largest US technology and entertainment companies and force an overhaul of their business practices.

In a bid to ward off corporate consolidation, the measures would make it harder for mega-companies like Amazon and Google to buy out smaller competitors, and facilitate the breakup of firms that use their dominant position in their core business to make deep inroads into another.

"Right now, unregulated tech monopolies have too much power over our economy," the House Judiciary's Antitrust Subcommittee chairman David Cicilline, a Democrat, said in introducing the measures.

"They are in a unique position to pick winners and losers, destroy small businesses, raise prices on consumers, and put folks out of work."

The goal, he said, is to "level the playing field" and ensure that powerful tech companies follow the same rules as other businesses.

The bills follow a 16-month investigation by the Antitrust Subcommittee into the state of competition in the digital marketplace, and particularly the unregulated power wielded by Amazon, Apple, Facebook, and Google.

Silicon Valley giants have come under increasing fire in Europe and the United States due to concerns about monopoly-like power.

And US President Joe Biden and other G7 countries are keen to set a global tax rate of at least 15 percent on multinational firms, in a bid to optimize tax revenue from tech behemoths.

The antitrust bills need to be debated and voted favourably out of the Judiciary Committee before receiving a vote by the full House of Representatives. They would also need approval from the Senate before they could be signed into law by Biden.

One of the bills increases the fees for mergers so that regulators have more funds to police corporations and enforce antitrust laws.

"Big Tech has abused its dominance in the marketplace to crush competitors, censor speech, and control how we see and understand the world," said House Republican Ken Buck, who took direct aim at some of the largest players.

"Apple, Amazon, Facebook, and Google have prioritized power over innovation and harmed American businesses and consumers in the process."