Dell's attempts to enter the smartphone market have been rejected by mobile phone operators not interested in offering the devices, reports suggest.

Shaw Wu, an analyst at Kaufman Bros, has published a research note about the situation, revealing that potential Dell partners were not impressed with the handsets the company had come up with.

Wu states that Dell built prototypes using both the Windows Mobile and Android operating systems, but the devices were rejected on the basis of "lack of differentiation" from current and coming-soon products from the big phone companies.

The analyst claims that Dell has not given up after this knock-back and "remains committed to the cell phone space as it appreciates the opportunity in smart phones and the longer-term cannibalization potential of PCs".

Wu says Dell is "going back to the drawing board is designing a cell phone with more differentiation" and may look at acquiring a phone or software company to help it get to market.