Nov 1 (Reuters) - Bayer investor Union Investment said on Wednesday the German group should reconsider its litigation strategy for glyphosate after it lost a trial over the weed killer's alleged carcinogenic effects for a third time in a row.

A California jury on Tuesday found Bayer liable in a case brought by a man who claimed his cancer was due to exposure to the company's glyphosate-based Roundup weed killer and ordered it to pay $332 million in damages.

The jury verdict was the third defeat for Bayer, after the company was ordered to pay a total of $175 million and $1.25 million in two other Roundup lawsuits.

Bayer said it would appeal in all three cases.

Before the three consecutive losses, Bayer had won nine cases in a row.

"Bayer's strategy is to file lawsuits only when it believes it has a good chance of winning. This has worked nine times, however has now failed thrice" said Markus Manns, a fund manager at Union Investment.

"Bayer should review its strategy again now to avoid further negative headlines," he added.

Union Investment has a 1.14% stake in Bayer, making it one of the 10 largest shareholders, according to LSEG data.

Mann said Bayer was rightly trying to avoid an expensive settlement with all the plaintiffs right away, in view of its difficult cash situation and high levels of debt, while acknowledging it would "be a difficult balancing act for Bayer".

At the last count, settlements were still pending in 47,000 of the approximately 160,000 claims filed, according to Bayer.

In August, Bayer CEO Bill Anderson underscored his predecessor's hawkish stance on the readiness to settle remaining glyphosate litigation.

"We have to be very tough in the face of our opponents who see us as a place to make a good business and we intend to defend our company's interest to the fullest," he said. (Reporting by Patricia Weiss Writing by Tristan Veyet Editing by Ludwig Burger and Mark Potter)