Updated from 12:01 p.m. EST The Securities and Exchange Commission took the unusual step Monday of suspending trading in A.C.L.N. ( ASW), and the Big Board quickly moved to delist the stock. A.C.L.N., a Belgium-based company that sells European used cars in Africa, has been plagued by questions over its bookkeeping for several months. In early January, the SEC launched an investigation into the company's disclosures. Last week, three of the company's board members resigned because of concerns over the investigation; also last week, A.C.L.N. said it would delay reporting fourth-quarter results. A.C.L.N. stock was halted at $8.35. The shares, which touched $50 in early September before dropping into the mid-$30 range during the fall, plunged into single digits in December following press reports questioning details about the company's operations and disclosure practices. Following the SEC's action, the New York Stock Exchange said it had moved to delist ACLN shares. "One of the factors noted in the Exchange's continued listing criteria that may lead to a company's delisting is conduct not in keeping with sound public policy," noted the NYSE in a press release. A spokeswoman for the exchange said that ACLN was "never going to open again" for trading on the Big Board. In calling for the trading halt, which is to last until midnight, April 2, the SEC cited several concerns, some of which already have been raised in the press ( most frequently by TheStreet.com's Herb Greenberg). These include A.C.L.N.'s revenue and income statements; its claim to ownership of its one ship, the Sea Atef; and its claim, within a press release, to have acquired ownership interest in five companies, each of which owns a car-carrier vessel. Unreported until now, the SEC also said it had questions regarding the business relationship between A.C.L.N. and Matina Forwarding & Trading. A.C.L.N. claims to have only four employees, and to conduct its business through MFT, an Antwerp-based company. The SEC also said it has questions about a source of funds A.C.L.N. claims as an asset deposited at the BNP Paribas Bank in Luxembourg. Finally, the SEC says that A.C.L.N. didn't disclose a Tunisian arrest warrant, outstanding from 1992, on president, CEO and managing director Abderrazak Labiadh (better known to A.C.L.N. shareholders as Aldo Labiad). Labiadh allegedly misappropriated funds from a Tunisian company he founded. Richard Sauer, SEC assistant director of the division of enforcement, said that the halt shouldn't be construed as a verdict of guilt. Rather, the SEC has decided that the information available on A.C.L.N. is too foggy for investors to know exactly what's going on. "At this point there isn't verifiable public information about it that would support a public market stock," he says. The last time the SEC ordered a halt on a New York Stock Exchange-listed stock was 1975.