FRANKFURT (Reuters) - Bayer’s CEO and two fellow executive board members purchased a collective 2.9 million euros ($3.5 million) worth of the German drugmaker’s shares after the stock was battered by billions in writedowns, litigation woes and a bleaker profit outlook. Bayer Chief Executive Werner Baumann and his wife Corinna purchased a combined 2.45 million euros in shares on Wednesday, according to regulatory filings posted by the company on Friday. Finance chief Wolfgang Nickl and consumer health head Heiko Schipper also bought stakes worth 154,000 euros and 309,000 euros, respectively, on the same day. Bayer shares have lost more than a fifth of their value since Sept. 30, when the group warned of billions of euros in impairment charges on agricultural assets and a slight decline in core earnings per share in 2021. Those writedowns amounted to 9.25 billion euros, the company said when it announced quarterly results on Tuesday, also flagging an increase of around $750 million in the cost of settlement terms with U.S. plaintiffs over its Roundup weed killer. The litigation over claims that Roundup causes cancer, which Bayer is seeking to settle for more than $11 billion, has also dragged the stock lower. A Bayer spokesman would not comment beyond the filings. Top executives are banned from buying or selling stock in their own company in the weeks running up to quarterly results announcements but are free to do so at other times.