Bain Capital increased its investment in II-VI Inc. to aid the Clinton Township-based business' acquisition of an industrial laser manufacturer and supplier.

In a news release sent Wednesday, II-VI announced Bain Capital LP agreed to purchase an additional $350 million in II-VI stock to help finance the Clinton business' acquisition of Coherent Inc., a California business, in a cash-and-stock transaction valued at $7 billion.

With Bain's additional equity investment, it will have purchased a total of $2.15 billion of II-VI's Series B convertible preferred stock. The company's final, $350 million investment will occur only immediately prior to the acquisition.

Bain's convertible preferred stock will be convertible to II-VI common stock at a conversion price of $85 per share, three years after issuance if the common stock price is more than $127.50 for 20 of any 30 consecutive trading days.

The Bain investment will enable II-VI to significantly reduce its leverage as a result of the deal, which is financed with cash on hand, about $5.4 million in debt financing from J.P. Morgan Securities LLC and the investment from BCPE Watson SPV LP, a Bain affiliate. The J.P. Morgan financing will likely have an interest rate of around 3.6%, an II-VI official said in March.

The 180,000 shares already purchased by Bain Capital became voting shares on June 3, and Bain co-chairman Steve Pagliuca is expected to join the II-VI board along with two Coherent directors, who will join upon the closing of the acquisition.

When the deal was announced in March, II-VI touted the two companies combined will produce roughly $4.1 billion annually in revenue. A March press release stated the transaction will likely accrete to II-VI's earnings per share in the second year after closing.

Coherent shareholders, who will be given $220 and 0.91 II-VI shares for each Coherent share owned, are expected to own roughly one-fifth of the combined company's stock when the deal closes.