VANCOUVER (Reuters) - Pacific Rubiales Energy Corp (>> Pacific Rubiales Energy Corp) said on Thursday it has postponed a shareholder vote on its planned C$2 billion ($1.6 billion) takeover by Alfa SAB de CV (>> Alfa SAB de CV) and Harbour Energy Ltd at the request of the bidding companies.

The vote, originally set for next week in Vancouver, has been pushed back to July 28.

A group of shareholders led by O'Hara Administration Co has launched a proxy battle to try to block the C$6.50 per share deal, saying it undervalues the company and does not benefit the shareholders.

The offer from Alfa and Harbour Energy came during difficult times for Pacific Rubiales, whose shares have plunged 75 percent over the last year as crude prices fell and the company struggled under a hefty debt load.

The stock closed up 7 percent at C$5.04 on Thursday on the Toronto Stock Exchange.

(Reporting by Julie Gordon; Editing by Leslie Adler)

Stocks treated in this article : Pacific Rubiales Energy Corp, Alfa SAB de CV