Maxwell Technologies Inc., San Diego manufacturers of energy storage devices used in hybrid buses, reported several financial metrics for the fourth quarter of 2012 and first quarter of this year, not including revenue and net profits.

The firm said its invoiced shipments were $42 million for the fourth quarter and $46.6 million for the first quarter of 2013. Other metrics released by the company included cash at the end of the periods, days of shipments outstanding, and debt obligations.

Maxwell is in the middle of amending its financial statements after the company found problems with its audited statements for 2011 and the first three quarters of 2012. The company said it was restating the financials for those periods “to correct revenue recognition errors in those statements.”

In an earlier report, Maxwell said the errors in the reports “related to the timing of recognition of revenue from sales to certain distributors.”

Following an internal probe, Maxwell said it terminated several employees. The company's auditor resigned.

Earlier this month, Maxwell said it hired new auditor. That firm is in the process of reviewing Maxwell’s financial reports for 2010 to 2012 and the first quarter of 2013. It’s also working with management to develop a schedule for filing new financial statements with the Securities and Exchange Commission, Maxwell said.

After Maxwell revealed the financial report problems in March, it was hit by several shareholder class action lawsuits against both the company and current and former officers and directors, which were consolidated into a single class action suit.

Shares of Maxwell, traded on Nasdaq under MXWL, have fallen from about $10 in early March to just above $6 in recent action.

— Mike Allen