WASHINGTON (Reuters) - Tech companies clashed with internet service providers on Monday over whether a landmark 2015 net neutrality order barring the blocking or slowing of web content should be scrapped by the U.S. Federal Communications Commission.

A group representing major technology firms including Alphabet Inc GOOGL.O and Facebook Inc FB.O urged the FCC to abandon plans to rescind the rules barring internet service providers from hindering consumer access to web content or offering paid "fast lanes."

The Internet Association said in its filing with the FCC that dismantling the rules “will create significant uncertainty in the market and upset the careful balance that has led to the current virtuous circle of innovation in the broadband ecosystem.”

The rollback would harm consumers, added the group, which also represents Amazon.com Inc AMZN.O, Microsoft Inc MSFT.O, Netflix Inc NFLX.O, Twitter Inc TWTR.N and Snap Inc SNAP.N.

Major internet service providers including AT&T Inc T.N, Comcast Corp CMCSA.O and Charter Communications Inc CHTR.O urged the FCC, however, to reverse the rules enacted during former President Barack Obama's administration, even as they vowed not to hinder internet access.

Verizon Communications Inc VZ.N said the Obama order had "injected uncertainty into the marketplace, restricted innovation, and chilled investment." It called the prospect of future rate regulation "a toxic approach if the goal is to encourage investment or the entrance of new competitors into the market."

Comcast said the order “represented an unfortunate, unnecessary, and profoundly unwise wrong-turn for the broadband economy and consumers more broadly.” AT&T said the FCC in 2015 “grossly exaggerated the need for public-utility-style regulation while ignoring its costs.”

White House spokesman Sean Spicer declined to weigh in on Monday, noting the FCC was an independent agency.

‘PAID PRIORITIZATION’

FILE PHOTO - The Federal Communications Commission (FCC) logo is seen before the FCC Net Neutrality hearing in Washington February 26, 2015. REUTERS/Yuri Gripas

In May, the FCC voted 2-1 to advance Republican FCC Chairman Ajit Pai’s plan to withdraw the former Obama administration’s order reclassifying internet service providers as if they were utilities.

Pai has asked that if in the event the FCC reverses that order, whether it has the authority or should keep any regulations limiting internet providers’ ability to block, throttle or offer “fast lanes” to some websites, known as “paid prioritization.”

Pai, who argues the Obama order was unnecessary and harms jobs and investment, has not committed to retaining any rules, but said he favors an “open internet.”

The Internet Association said there was “no reliable evidence” that investment by providers had fallen.

Twelve state attorneys general including from Illinois and California urged the FCC not to overturn the Obama rules, saying that would “expose consumers to the risk that their internet access will be interfered with and disrupted.”

More than 8.4 million public comments have been filed on the proposal. Pai will face questions on Wednesday on the issue at a U.S. Senate hearing.

Providers say they strongly support open internet rules and will not block or throttle legal websites even without legal requirements.

But some providers have said paid prioritization may make sense at times, citing self-driving cars and healthcare information.

The Internet Association said it was “open to alternative legal bases for the rules, either via legislative action codifying the existing net neutrality rules or via sound legal theories offered by the commission.”

But it said Pai’s proposal “offers no clear alternatives.”