Cox Enterprises Inc. has been exploring a sale of its online automotive classifieds unit, AutoTrader.com but took the company off the market Tuesday, according to an internal document obtained by Ward’s.

Chip Perry, AutoTrader.com’s president, confirms Cox was considering a sale but says Cox has decided to terminate the sales process and not sell AutoTrader at this time.

Perry declined to comment whether Cox would reopen the sales process in the future.

The potential sale was part of a larger effort by Cox to reduce its debt.

According to the document, Cox retained investment banker Goldman Sachs and Co. to explore a potential sale nearly two months ago, just before the credit meltdown.

Sources say the process didn’t get far enough with interested buyers to determine a possible price. Although there were several interested purchasers, the current market environment makes it difficult to contemplate such a large transaction.

AutoTrader.com is estimating 23% growth in revenue this year to $635 million. It has some 2,600 employees and with 14.9 million unique visitors, it is one of the leading online automotive services.

Perry says AutoTrader is having a good year, despite difficult market conditions primarily because dealers and auto makers continue to increase their investment in Internet advertising while overall marketing spend is down.

cbanks@wardsauto.com