* Exec board gets 44.5 pct approval vote
* Bayer AGM held on Friday
* Shares have slumped in wake of glyphosate litigation (Adds investor quote, voting percentage)
By Ludwig Burger
BONN, April 26 (Reuters) - Bayer shareholders on Friday cast a vote of disapproval of the German drugmaker's top management amid anger over a stock price slump as litigation risks mount from the $63 billion takeover of seed maker Monsanto.
A 55.5 percent majority of shareholders at its annual general meeting voted against ratifying the executive board's business conduct during 2018, the company said.
Such a vote, which features prominently at every German AGM, is largely symbolic because it has no bearing on management's liability or tenure but it is seen as a key gauge of investor sentiment.
Bayer's non-executive supervisory board, in turn, won a 66.4 percent majority of the votes ratifying its business conduct during 2018, the spokesman said.
About 30 billion euros ($34 billion) have been wiped off Bayer's market value since August, when a U.S. jury found the pesticide and drugs group liable because Monsanto had not warned of alleged cancer risks linked to its weedkiller Roundup.
Bayer suffered a similar defeat last month, while more than 13,000 plaintiffs are claiming damages.
Bayer is appealing or plans to appeal the verdicts and has pointed to global regulators' findings that the use of glyphosate, the active ingredient in Roundup, is safe.
No incumbent executive board members at companies listed in Germany's blue-chip index DAX has flunked the vote, meaning receiving an approval vote of less than 50 percent at an AGM. Approval rates above 95 percent are typical results.
In a recent low for a company leadership team, former Deutsche Bank co-CEOs Anshu Jain and Juergen Fitschen scored approval ratings of about 61 percent during the bank's 2015 AGM. Both announced their resignation within weeks.
Top 20 Bayer investors who earlier on Friday said they would cast a 'no' vote included Deka Investment and Union Investment.
"The vote is a disgrace. To be gambling away the trust of so many investors within such a short time has historic proportions," said Ingo Speich, head of sustainability and corporate governance at Deka Investment.
He added he hoped management will listen more to shareholders in future.
This month, shareholder advisory firms Institutional Shareholder Services (ISS) and Glass Lewis recommended that investors not give the executive board their seal of approval.
Earlier on Friday, various shareholders vented their anger at the AGM.
CEO Baumann said Bayer's true value was not reflected in the current share price.
"There's no way to make this look good. The lawsuits and the first verdicts weigh heavily on our company and it's a concern for many people," he said, adding it was the right decision to buy Monsanto and that Bayer was vigorously defending itself. (Reporting by Ludwig Burger Editing by James Dalgleish)