At a time when recorded jazz of any kind is not generally viewed as a big-selling item and traditional jazz is considered a minor element within this limited field, it is surprising to find a record company that, since the beginning of the 1980's, has recorded and released more than 100 new, state-of-the-art LP's devoted to jazz in the styles of the 1920's or earlier, as played by contemporary musicians.

Stomp Off Records, which was launched in 1980 by Bob Erdos with money from the sale of his interest in Danskin, a manufacturer of clothing for dancers, has just published a catalogue of its first 100 LP's. It lists more than 70 different performing groups, made up of musicians based throughout Europe and Scandinavia, as well as in Japan and the United States. A dozen of the earliest of these albums are already collector's items, no longer available. Among them are disks by the Peruna Jazzmen of Copenhagen, the Swedish band Scaniazz, the High Society Jazz Band of Paris and such American groups as Terry Waldo's Gutbucket Syncopators, the Golden State Jazz Band and the State Street Aces, as well as the pianists Tom Shea, Ray Smith and Gale Foehner.

Mr. Erdos's early emphasis in his recordings was on style. Most of the bands he recorded were patterned on one or more jazz groups of the 20's, and although they often followed fairly closely the performances recorded then, the musicians in the Stomp Off bands tended to be so steeped in these styles that they used them only as a foundation on which they built their individual manners of playing.

Once the fact was established that there were many present-day musicians playing - and playing well - in these older styles, a listener's attention moved to the second part of Mr. Erdos's purpose in establishing his record company - keeping the repertory of the period alive. The catalogue lists more than 1,000 tunes already on his records, which may come as a surprise to those who think of the traditional jazz repertory as repetitions of a handful of tunes stretching from ''Muskrat Ramble'' to ''When the Saints Come Marching In.'' As a matter of fact, neither one of those tunes has appeared as yet on a Stomp Off record. The most frequently recorded tune in the catalogue is ''Candy Lips (I'm Stuck on You),'' which is on seven LP's, followed by ''Papa De-Da-Da'' and ''Perdido Street Blues'' on six.

In its most recent batch of releases (10 releases twice a year is Mr. Erdos's quota), Stomp Off, while keeping its inspiration in the past, is becoming positively innovative. The newest records include a set of banjo and tuba duets with vocals, a series of disks dealing with the music and the musicians associated with Storyville, the New Orleans red light district at the turn of the century, around which much early jazz legend grew up, and programs which draw on as ''modern'' a group as the John Kirby Sextet of the late 30's and early 40's.