Chatsworth toy manufacturer MGA Entertainment Inc. made a bid last month to merge with rival toy company Mattel Inc., in El Segundo, which rejected the offer.

In a letter sent to Mattel Chief Executive Ynon Kreiz on May 12, MGA Chief Executive Isaac Larian pointed out Mattel’s recent financial struggles including three consecutive years of declining sales, a 37 percent drop in stock price over the last 12 months, and $2.2 billion in net debt. Larian did not specify an exact price for the proposed merger but said it would be at a premium to Mattel’s current market value.

The offer also stipulated that Larian would become Mattel’s chairman and chief executive and that all of Mattel’s current board members would resign with no further compensation.

Mattel’s Chief Legal Officer Bob Normile wrote in response that the company’s board “unanimously concluded that (MGA’s) proposal is not in the best interests of Mattel and its shareholders,” and that the company is not interested in further negotiations.

This is not the first time Larian has tried to merge the companies. He first made overtures to Mattel in April 2018 that proved unsuccessful.

Given the bad blood between MGA and Mattel, the offer may have been made in jest as a publicity stunt — the rivals are currently at odds over a $1 billion lawsuit in which MGA accuses Mattel of spying on competitors and stealing confidential information. This lawsuit follows a decade-long legal feud in which Mattel accused MGA of copyright theft after a Mattel employee sold MGA the idea for the Bratz line of dolls. Larian’s merger offer included Mattel settling its $1 billion lawsuit with MGA and spinning the payout into equity of the merged company.

Mattel makes toys for high-profile brands like Barbie, Fisher-Price, Hot Wheels and American Girl, and recently signed a licensing deal for Hello Kitty and Friends. MGA makes Bratz dolls, Little Tikes and L.O.L Surprise! dolls — one of 2018’s most popular toys.

News of Larian’s offer sent shares of Mattel (MAT) up 57 cents, or 5.3 percent, on Wednesday to $11.38 on the Nasdaq. On Thursday, shares gained 38 cents to close at $11.73.