* Watchdog says Equifax used undue pressure, unfair tactics

* U.S. parent facing SEC suit for insider trading in cyber-attack

* Equifax acknowledges "unsatisfactory" experience for customers

By Paulina Duran

SYDNEY, March 16 (Reuters) - Australia's competition regulator said on Friday it was suing credit reporting company Equifax Pty Ltd, owned by U.S.-based Equifax Inc, alleging it misled consumers and used unfair tactics with people in financial hardship.

The alleged consumer law breaches by Equifax's Australian unit, which it bought in February 2016 and rebranded from Veda Advantage, mark the second legal challenge this week involving the Atlanta-based company.

The Australian Competition and Consumer Commission (ACCC) alleged that from June 2013 to March 2017, Equifax misled consumers, telling them its paid credit reports provided more complete information than its free reports, which they did not.

"It is alleged that Equifax acted unconscionably in its dealings with vulnerable consumers including by making false or misleading representations, and using unfair tactics and undue pressure when dealing with people in financial hardship," the ACCC said.

The allegations come just days after the U.S. government filed criminal and civil charges against a former Equifax executive over alleged insider trading linked to last year's massive data breach at the credit reporting company

That was the first time that the U.S. government had pursued insider trading charges against somebody accused of profiting from information about a cyber attack.

In Australia, the ACCC also alleged Equifax told customers they had to buy reports if they wanted to edit their own credit history, when in fact the company was required by law to take "reasonable steps" to keep accurate and current records.

"We allege that Equifax told people they needed to buy credit reporting services from them in situations when they did not," ACCC Commissioner Sarah Court said.

Equifax said in an emailed statement it had "fully cooperated" with the ACCC's investigation and was reviewing the allegations.

"We acknowledge that the experience was unsatisfactory for some consumers when dealing with Equifax and we are carefully reviewing our processes and making changes to improve that," Mike Cutter, Asia Pacific Managing Director said. (Reporting by Paulina Duran; editing by Richard Pullin)