Aug 19 (Reuters) - Depomed Inc rejected Horizon Pharma Plc's takeover bid for the third time, reiterating that the offer undervalued the company.

Depomed said Horizon Pharma's latest all-stock bid had a current value of $30 per share, or about $1.81 billion, lower than Horizon's previous offer of $33.

Horizon Pharma said last Thursday it would offer 0.95 Horizon Pharma shares for every Depomed share. It had also said it could alternatively offer Depomed shareholders $32.50 in cash and stock.

Horizon Pharma first approached Depomed in May and went hostile with its offer in July after being rejected. Depomed adopted a poison pill to stave off the bid.

Up to Wednesday's close of $31.27, Horizon Pharma's stock had fallen about 4 percent since its initial offer on May 27th.

(Reporting by Anet Josline Pinto in Bengaluru; Editing by Saumyadeb Chakrabarty)