Cash and Cash Equivalents, Restricted Time Deposits and Marketable Securities

MRV treats highly liquid investments with an original maturity of 90 days or less as cash equivalents. Investments with maturities of less than one year are considered short-term. MRV maintains cash balances and investments in qualified financial institutions, and at various times such amounts are in excess of federal insured limits.

Restricted time deposits represent investments that are restricted as to withdrawal or use and are primarily in foreign subsidiaries. Restricted time deposits generally secure standby letters of credit, bank lines of credit, or bank loans. Investments in and releases of restricted time deposits are included in investing activities on the Company's Statement of Cash Flows unless the time deposits relate to an underlying bank loan and will be used to repay the loan, in which case the related cash flows are treated as financing activities.

MRV accounts for its marketable securities, which are available for sale, under the provisions of ASC 320-10 Accounting for Certain Investments in Debt and Equity Securities. The original cost of MRV's marketable securities approximated fair market value as of December 31, 2010. Unrealized losses at December 31, 2010 were $39,000.

Marketable securities consisted of the following (in thousands):



	September 30, 2011		December 31, 2010
U.S. government issues	$	—	$	11,699
Corporate issues	—		1,775
Total	$	—	$	13,474