The onetime subsidiary of bankrupt SemGroup LP filed the report Friday with the SEC but did not issue a press release. The Tulsa-based company’s Web site does not mention the second-quarter earnings statement.

SemGroup Energy Partners, also known as SGLP, was due to release its second-quarter report by May. The midstream energy company, however, has been hobbled by financial issues related to the bankruptcy of its former parent.

In fact, SGLP’s second-quarter earnings will have to be announced this month to meet guidelines for stock exchanges such as Nasdaq. Nasdaq delisted SGLP earlier this year after the company did not file its quarterlies for 10 months.

The weekend report indicated that net income was down more than $10 million from the $9.76 million profit in 2008’s second quarter. That quarter, however, included SemGroup LP’s financial collapse and bankruptcy in July 2008.

For its first quarter, SGLP has locked up third-party storage agreements for 45 of its 46 asphalt terminal facilities. The company still received 42 percent of its overall revenue from the parent SemGroup for the three months ending March 31.

Third-party revenue for crude oil storage and gathering services more than doubled to $14 million in the second quarter, compared with $5 million in the same period last year.

SGLP executives have not held a conference call to discuss earnings