TRADE RECEIVABLES

3 Months Ended

Mar. 31, 2013

TRADE RECEIVABLES [Abstract]

TRADE RECEIVABLES

4. TRADE RECEIVABLES

Trade receivables, net, at March 31, 2013, and December 31, 2012, consisted of the following:

	March 31, 2013			December 31, 2012
	(thousands of dollars)
Trade receivables	$	20,218		$	16,012
Less allowance for doubtful accounts		(210	)		(210	)
Trade receivables, net	$	20,008		$	15,802

Trade receivables serving as collateral for the Company's line of credit with a domestic bank were $15.6 million and $11.7 million at March 31, 2013, and December 31, 2012, respectively (see Note 8).