(Adds background, further detail, shares)
LONDON Aug 27 Swiss recruitment agency Adecco ADEN.VX has been set a deadline of 1600 GMT on Sept. 30 to decide whether to make a formal offer for British rival Michael Page MPI.L.
Under a ruling by the UK Takeover Panel on Wednesday, Adecco must announce either a firm intention to make an offer by that date or that it does not intend to make one. In the latter case, it will be prohibited from making an offer for Michael Page for six months following the announcement.
In a statement, the Takeover Panel said both parties has accepted the ruling.
Last week, Michael Page Chief Executive Steve Ingham urged the panel to issue a 'put up or shut up' notice of this kind to Adecco while speaking to Reuters in an interview.
However, he acknowledged the group's rejection of Adecco's 400 pence a share or 1.3 billion pound ($2.43 billion) offer proposal is "not the end of the matter".
Adecco said it will make a further announcement when appropriate but there is no assurance an offer will be made.
Michael Page declined to comment.
Shares in Michael Page were 0.6 percent lower at 347.5 pence at 1050 GMT. (Reporting by Matthew Scuffham; Editing by Quentin Bryar)