This excerpt taken from the E 20-F filed May 14, 2009.
In addition to the rules of Article 2359-bis of the Italian civil code governing the acquisition of shares of the parent company by a controlled subsidiary, Decree No. 58/1998 regulates additional cross-ownership matters as follows.
Cross-ownership between listed and non-listed companies may not exceed 2% of the shares of the listed company or 10% of the shares of the non-listed company (applying, for calculating these ownership thresholds, the same rules established for holdings in listed companies).
The company that last exceed the limit of 2% or 10% interest in a listed or unlisted company respectively, may not exercise the voting rights on the shares held in excess of such thresholds and must sell such shares within the following 12 months. In the event of failure to make the disposal within such time limit, the suspension of voting rights shall apply to the entire shareholding, and any resolution or act adopted with the contribution of relevant shares, could be challenged under the Civil Code.
If anyone holds an interest exceeding 2% of the share capital of a listed company, such listed company or any entity controlling such listed company may not acquire an interest exceeding 2% of the share capital of a listed company controlled by said holder. If the foregoing limit is exceeded, the holder who last exceeded the foregoing limit (or both the holders, if it is not possible to ascertain which holder exceeded such limit last) may not exercise the voting right related to the shares exceeding the foregoing limit. In the event of non-compliance, the voting rights attached to the shares in excess of the limit specified shall be suspended and any resolution or act adopted with the contribution of relevant shares, could be challenged under the Civil Code.
Described limitations are not applicable in case of a tender offer for acquiring at least 60% of the ordinary shares of a listed company. For a description of the limitation on cross-ownership between a company and its subsidiaries, see "Purchase by Eni SpA of its Own Shares".