Media giant CBS Corp is considering spinning off its internet businesses into a separate, publicly-traded company. On a conference call with analysts to discuss the company’s quarterly results, chief executive Mel Karmazin admitted that CBS is leaning towards floating its web-based assets, which include a 38% stake in Marketwatch.com and a 12.5% stake in SportsLine USA Inc. If this is where people want to be, we want to be there to sell them advertising and have a piece of their commerce, Karmazin said on the conference call. The idea is that shares in the new company, tentatively being called CBS.com would be used to invest in other internet-related businesses. One possible scenario raised by Karmazin is that the online unit would be jointly-owned by CBS and its separate radio unit, Infinity Broadcasting Corp. The news follows the successful initial public offering of Marketwatch.com last month and a similar announcement in December from General Electric Co, which said it was considering spinning off some of its NBC internet holdings. Karmazin tempered his enthusiasm, however, by saying that CBS wouldn’t allow its overall performance to be affected by spending on the internet.