Shares of Electronic Clearing House Inc. plunged more than 35 percent Tuesday after its merger with Intuit Inc. was scuttled amid a probe into the Camarillo company’s ties to online gaming.

Electronic Clearing House, which operates an electronic funds transfer service, said that it is cooperating with federal investigators in an investigation into services the company provided to online gaming Web sites and does not expect to be criminally prosecuted.

The company also said it agreed to pay a $2.3 million fine, which represents management’s estimate of the company’s profits from processing and collection services provided to its Internet customers since 2001.

The deal with Intuit, the financial software maker based in Mountain View, was announced last December and was reportedly worth $142 million, which valued shares of Electronic Clearing House at $18.75. Company shares were trading at just over $12 in afternoon trading Tuesday.

Electronic Clearing House and Intuit said they agreed to release each other from all claims.

As a result of the nixed merger and the federal investigation, Electronic Clearing House said it has incurred additional expenses that will hurt near-term financial results. It also delayed the expected release Tuesday of its quarterly earnings.