Activist shareholder Perpetual Ltd. believes that KKR & Co.'s bid to acquire Telepizza Group at €6 per share undervalues the Spanish pizza delivery company by about 17%, Bloomberg News reported.

In a letter seen by the news outlet, Perpetual's Garry Laurence called the private equity giant's takeover offer, which reflects a company valuation of €432 million, an opportunistic attempt to take advantage of the skittish market. He reportedly argued that Telepizza should be worth between €7 and €10 per share.

Laurence holds 3.04 million shares and has backing from three other shareholders, according to Bloomberg.