Japan’s best-known activist investor, Yoshiaki Murakami, announced a tender offer for Toshiba Machine Co., one of the entities embroiled in a controversial takeover battle for NuFlare Technology Inc.

The bid late Friday with funds from investment company Office Support, backed by Murakami, came just hours after Toshiba Machine confirmed it had agreed to tender its shares in NuFlare to Toshiba Corp. for ¥11,900 apiece. The electronics maker was able to clinch the unusual bidding war, which included Murakami’s funds, even though Hoya Corp. had offered to pay a higher price of ¥12,900 for each NuFlare share.

Murakami appears to be seeking to disrupt or derail the NuFlare deal, even though Toshiba said the same day that it had secured enough shares to proceed with a takeover of NuFlare. The purchase was seen as a snub to minority shareholders because Toshiba was already NuFlare’s largest stakeholder with 52.4 percent when it started the buyout. Toshiba Machine, an independent company that retains the former parent’s name and is the second-largest NuFlare stockholder, had agreed to sell its 15.8 percent stake to Toshiba.

Toshiba Machine said it had not been consulted at all in advance of the Murakami bid and that a committee would evaluate the proposal. It also said it could block the offer with the issuance of share warrants.

It has been a busy weekend for Toshiba, which has been in almost constant turmoil since an accounting scandal erupted in 2015. The Tokyo-based company has seen executive resignations, multibillion-dollar losses in its U.S. nuclear business and the sale of its crown-jewel memory-chip unit.

Separately on Saturday, Toshiba said that Chief Executive Officer Nobuaki Kurumatani will be taking on the additional title of president as part of a revamp of top management aimed at speeding up decision making. And in yet another announcement, Toshiba said a subsidiary called Toshiba IT-Services Corp. may have misreported as much as ¥20 billion in sales.

Friday’s statement by Toshiba Machine did not give an offer price or an indication of how much Murakami entities were prepared to spend, but said the bid would begin Tuesday.Murakami funds already effectively held 11.5 percent of Toshiba Machine, the statement said.

Last month, Minami Aoyama Fudosan, another fund linked to Murakami, reported it had a stake in NuFlare, a provider of equipment used to make computer chips, and said it may give advice or make proposals to management.

Murakami is considered one of the pioneers in Japan’s battle for shareholder rights and he put forward the first hostile takeover bid by an investor in the country. In 2007 he was convicted for insider trading and sentenced to two years in prison, which was suspended on appeal.

Hoya offered to spend as much as ¥148 billion for NuFlare, seeking a minimum of 66.7 percent of the company. At the time, Hoya said it had not discussed the bid with NuFlare or Toshiba in advance for fear of the information leaking out and driving up the price. Toshiba’s Kurumatani has said that NuFlare would not be able to survive outside of the group and he has no plans to sell his stake. After Toshiba’s announcement, Hoya said it would not pursue its tender any further.

“We saw it as a 50-50 chance to begin with,” said Taishi Arashida, a spokesman for Hoya. Arashida said there is still room to discuss acquisition or some kind of a partnership with Toshiba.

NuFlare dominates the market for mask writers, used for imprinting patterns on glass squares slightly bigger than a CD case that act as a stencil for semiconductor designs. Hoya is one of only two companies in the world — the other being Japanese compatriot AGC Inc. — capable of making the blank masks used in next-generation extreme ultraviolet lithography, and it sees a lot of synergy between itself and the acquisition target.

Toshiba hasn’t explained how it arrived at the offer price and it is not clear how NuFlare fits into the company’s business portfolio, given that chip manufacturing hasn’t been core to its business after it spun off memory operations in 2018.

NuFlare has said that it saw Toshiba’s bid as the best way to increase the company’s value and that the two of its 10 board directors who had connections to Toshiba group recused themselves from voting on the matter.