Helionetics was threatened with foreclosure.

The ailing Irvine defense contractor said that one of its principal lenders is threatening to foreclose on a $4.5-million loan this week. Helionetics President Michael Mann said the company would file for bankruptcy protection before letting the lender, Downey Savings & Loan Assn. of Costa Mesa, force an asset sale. In an unrelated matter, the company confirmed that founder Bernard Katz and Chairman Wilson Talley resigned from its board earlier this month, just weeks after four other board members quit.