New shots were fired Wednesday in the increasingly contentious takeover battle for Coherent (COHR). The two leading contenders to acquire the laser technology company, Lumentum Holdings (LITE -0.12%) and II-VI (COHR 1.50%) both submitted fresh bids to gain the upper hand.

The earlier of the two was Lumentum's. The company increased its offer to $220 per share in cash and 0.61 of a share of its own stock per Coherent share, for a total of roughly $275 per share. It added that private equity firm Silver Lake Capital will also make a $1 billion equity investment in the combined company.

Several hands holding up bills of U.S. currency.

Image source: Getty Images.

Coherent reacted to Lumentum's new offer in a press release, writing that its board of directors will "carefully review" it, in consultation with its legal and financial advisors.

That evening, II-VI apparently also submitted a new offer. The Wall Street Journal reported late Wednesday evening that II-VI had also sweetened its bid. Citing "people familiar with the matter," the report indicates that II-VI upped its offer $220 per share (from the previous $195). Like Lumentum, II-VI is also offering stock, and while the Journal didn't specify the mix between cash and stock, it did write that the total bid comes to around $285 per share.

The Coherent takeover saga began in mid-January, when the company agreed to be acquired by Lumentum, for $100 per share in cash and just under 1.19 shares of Lumentum stock for every share of Coherent. But II-VI and MKS Instruments (MKSI 2.19%) soon stepped in with competing offers, and the battle was on.

It seems that MKS did not submit a new bid of its own on Wednesday; its last known one was made on March 8, for a total of $250 per share in cash and stock.

It's still to be determined how much longer this bidding war will continue.