HZN up ROC down, page-11

Further, I think the following excerp from the HZN announcement explains the position:

"At this time, Horizon Oil does not have any further information in relation to the identity of the other party, the material details of the approach or whether discussions are continuing between Roc Oil and the third party. Accordingly, it is unclear whether this approach will eventuate or affect the timing of the proposed Merger.
If a competing proposal does emerge, Horizon Oil will assess its position (including preservation of its rights under the MID) having regard to all available information at that time.
At this stage, Horizon Oil does not make any recommendation or express any view to Horizon Oil shareholders in relation to this matter. Horizon Oil will keep shareholders informed of any material developments."

regards
DF