Mattel Inc. rejected MGA Entertainment Inc. CEO and owner Isaac Larian's offer to merge his company with the rival toymaker, The Wall Street Journal reported, citing correspondence reviewed by the publication and people familiar with the matter.

The proposal, with undisclosed details and financial terms, was made by Larian in an April 25 letter less than a week after Mattel replaced CEO Margo Georgiadis with Ynon Kreiz after she was reportedly unable to counter the company's sales slump, the Journal said.

According to the report, Mattel replied to Larian's letter on May 17, saying the offer, which would place him at the head of the combined companies, was not in the best interests of the company. Mattel also reportedly said it is not interested in further discussions with Larian, whose company makes Bratz Dolls.

Despite the rejection, a Mattel spokesman said in a statement to the Journal that the board takes seriously its duty to consider any credible proposal.

Larian, however, said the rejection was "disappointing" and an "arrogant" move by the maker of Barbie dolls, according to the report, and added that he intends to take his offer directly to shareholders.