UPDATE: Private-Equity Firms and ST Engineering in Bidding War for Cubic Corp

After Veritas and Elliott pairing raised its offer to $72 a share, ST Engineering responded by boosting its to $78. A bidding war has erupted around defense- and transit-technology company Cubic Corp. , which had agreed to sell itself to a pair of private-equity firms before a new corporate suitor surfaced last week.

Veritas Capital and the private-equity arm of Elliott Management Corp. in February agreed to pay $70 a share to take Cubic private. Singapore Technologies Engineering Ltd. then made an unsolicited bid of $76 last week.

Since then, the private-equity duo raised its bid to $72 a share, and ST Engineering responded by boosting its offer to $78, according to people familiar with the matter.

ST Engineering disclosed its increased bid late Monday after The Wall Street Journal reported on it.

Cubic shares rose 1.7% Monday, and closed at $76.05.