Cable sets blue plate specials.

While the prospect of cable operators offering a la carte pricing any time soon remains slim, the discounted tier is clearly taking root.

In the wake of a wave of subscriber losses that cable operators contend are largely driven by the shaky economy, Comcast has quietly expanded a low-cost trial offering in select markets that not only provides fewer channels than basic cable but additional options that group together select channels by programming genre.

The package, known as MyTV Choice, began testing in Charleston, S.C. last week, after being deployed in western New England and Seattle over the summer.

The expansion comes on the heels of Time Warner …