WILMINGTON, Delaware, Jan 21 (Reuters) - Meta Platforms' ( META )

former chief operating officer, Sheryl Sandberg, was

sanctioned by a judge on Tuesday for deleting emails related to

litigation over Facebook's Cambridge Analytica privacy scandal,

despite being told to preserve the messages.

The judge, Vice Chancellor Travis Laster, of Delaware

Chancery Court, said evidence showed Sandberg used a personal

account under a pseudonym and erased messages that were likely

relevant to the shareholder lawsuit.

The sanction will make it harder for Sandberg to tell her

side of the story and avoid liability at the eight-day, non-jury

trial scheduled for April. The judge also ordered her to pay the

expenses related to the sanctions motion incurred by the

shareholders, which include California's huge teachers'

retirement system known as CalSTRS.

"Because Sandberg selectively deleted items from her Gmail

account, it is likely that the most sensitive and probative

exchanges are gone," Laster wrote in his opinion published on

Tuesday.

Meta and an attorney for Sandberg did not immediately

respond to a request for comment.

Sandberg had argued she was forthcoming about the personal

account and rarely used it for business and when she did, others

were copied on the messages so the information was preserved.

Laster imposed a higher standard of "clear and convincing

evidence," rather than "preponderance" of evidence, for

Sandberg's affirmative defenses, which are her arguments and

evidence for why she should not be held liable.

The case was brought in 2018, when it emerged that Facebook

allowed data from millions of users to be accessed by Cambridge

Analytica, a political consulting firm that worked for Donald

Trump's successful campaign for U.S. president in 2016.

Shareholders sued the company's directors and officers for

allegedly harming investors by continually violating a 2012

consent order with the Federal Trade Commission to protect

users' data.

Shareholders also allege the company's board bargained to

pay a larger fine of $5 billion to the FTC in 2019 so that

founder Mark Zuckerberg would not have personal accountability.

Zuckerberg is expected to be deposed for a second time before

the start of the trial, according to court records.

In 2023, Laster refused to dismiss the lawsuit, which he

said was a "case involving alleged wrongdoing on a truly

colossal scale."

Shareholders also asked Laster to sanction Jeffrey Zients,

who was former President Joe Biden's chief of staff and who also

used and deleted personal emails when he was on Meta's board.

The judge said that Zients' messages were less pertinent because

he joined the Meta board in 2018, after the Cambridge Analytica

scandal, and was not a company officer.