STOCKHOLM, March 7 (Reuters) - Sweden's Economic Crime Authority is investigating eight suspected cases of insider trading in Scania shares in connection with majority owner Volkswagen's offer to buy out other shareholders in the Swedish truck maker.
Volkswagen, Europe's biggest carmaker, last month offered to buy out minority shareholders for 6.7 billion euros ($9.27 billion).
"Prosecutors have taken the decision to look at it more closely," a spokeswoman for the Economic Crime Authority said on Friday.
"The prosecutor has said it's a matter of millions of crowns. We cannot be more precise than that."
Insider trading is illegal when a person with access to confidential information about a company buys or sells its shares before the information is made public.
The spokeswoman declined to say what had prompted the authority's investigation.
Trading volumes in Scania were at a daily average of around 2.2 million shares in the three weeks before Volkswagen's bid on Feb. 21, when the truckmaker was the subject of rumours about a potential offer from its majority owner. That was slightly higher than a 90-day average of 2.06 million shares.
Scania shares rose by more than 30 percent to trade at 194.50 Swedish crowns ($30.4) on Feb. 24 - the first day of trade after Volkswagen's offer of 200 crowns per share.
The spokeswoman said that trades by two top Scania executives three weeks before the German carmaker's bid were not among the cases being investigated.
According to the Swedish Financial Surpervisory Authority's list of trades by company executives, both Chief Executive Martin Lundstedt and Chief Financial Executive Jan Ytterberg bought shares on Jan. 30, the day after Scania reported fourth-quarter earnings.
A Scania spokesman said none of Scania's five executive directors were being investigated.
A Volkswagen spokesman said the carmaker made its offer without prior contact with Scania's board. He declined to comment on the Swedish investigation.
Scania shares were trading slightly lower at 195.6 crowns at 1525 GMT, broadly in line with the Stockholm blue-chip index . ($1 = 6.4053 Swedish crowns) ($1 = 0.7225 euros) (Reporting by Helena Soderpalm; additional reporting by Arno Schuetze in Frankfurt; Editing by Erica Billingham)