Chemical Bank makes advertising history, perhaps next Friday, when it begins full-time local sponsorship of Louis Rukeyser's popular ''Wall Street Week'' program over WNET, Channel 13, New York's public-broadcasting station.
The show, which has been running Friday nights for a dozen years now, is also broadcast by most of the nearly 300 public television stations around the country.
Channel 13 is euphemistically referring to the three 15-second advertising spots N. W. Ayer has created for Chemical as ''enhanced underwriting messages. In return for the opportunity to speak its piece over noncommercial airwaves, the bank is paying the $167,000 annual cost of producing ''Wall Street Week,'' plus 15 percent for its ''message.''
Actually, Chemical Bank is not the station's first bona fide advertiser. Others, such as E. F. Hutton & Co. and Gucci, began running ''random program promotion spots'' late last year - commercials that run along with a promotion of a sponsored program. And the Texaco Philanthropic Foundation sponsored the Christmas telecast of the Metropolitan Opera's ''Hansel and Gretel,'' with ''enhanced underwriting messages'' before and after.
But Chemical Bank is the first real advertiser to sponsor a regular weekly program over Channel 13. If all goes as well as hoped, this is only a shadow of advertising yet to come.
New York's WNET is one of 10 PBS stations selected to take part in a program mandated by Congress to explore new ways to raise revenues - specifically, to test the advertising waters and see what they might hold for financially troubled public broadcasting.
This is an 18-month advertising experiment that began last January and will officially end June 30. Results will then be tabulated for a report to Congress by October.
The 10 participating PBS stations fall into three groups. One group of seven stations was first to air 30- or 60-second spots, or even two-minute messages. These seven stations are WHYY (12), Wilmington-Philadelphia; WQLN (54), Erie, Pa.; WPBT (2), Miami; WYES (12), New Orleans; WIPB (49), Muncie, Ind.; WTTW (11) , Chicago; and KCSM (60), San Mateo, Calif.
In Binghamton, N.Y., WSKG (46) is developing a ''membership swap'' in which not-for-profit organizations (colleges, say) can promote their services by offering station members (supporters among the public) a discount (reduced tuition fees, perhaps). It might be part of a membership drive. But this has yet to go on the air.
Somewhere in the middle, both chronologically and ideologically, are the two remaining stations in the test - WQED in Pittsburgh (13) and WNET, New York. According to Patsy Gesell, WNET's director of planning, the somewhat later start on the advertising experiment is because these stations, as program producers, had special problems to work out with copyrights and unions so as to maintain favorable cost structures during the testing period.
Miss Gesell said, ''Channel 13 retains full editorial control over the type and quality of the message being delivered. Our enhanced underwriting messages can be used for corporate advertising but not for product sell. These spots are being severely limited in length and at no time will they appear in the middle of a program.''
Sharon E. Baum, Chemical Bank vice-president and director of advertising, commented: ''This is such an efficient buy for us because 'Wall Street Week' specifically reaches our target market with almost no waste. It offers us program sponsorship at an attractive price during this time of reduced advertising budgets. We have a 52-week contract, which we hope can be extended beyond the official closing date in June.''
''As far as the 'message enhancements' are concerned, they are offered in two ways,'' Lewis I. Haber, WNET director of program marketing, explains. ''You can buy them as spots scattered throughout our programming or in the more traditional way, associated with a particular program, as was the case with Chemical Bank and Texaco. In general what we want to do is get access to the advertising and marketing dollar instead of public relations and (philanthropic) fund moneys, which seem to be shrinking along with governmental funding.
''Our experience so far is that the advertising community is interested,'' Mr. Haber reports. ''We've been getting many phone calls from advertising agencies who want to know more about what we have to offer.''
Some public-broadcast underwriters of long standing mix in a little caution with their enthusiasm about the experiment. John H. Childs, Texaco's general manager of worldwide advertising, says, ''We are very much interested in seeing how this experiment develops and its broad implications for PBS underwriters of national programs. While this may appear to be the most accessible avenue for improved financial conditions for PBS stations, some viewers may resent lengthened advertising identification, even though advertisers respond favorably to the longer reference (commercial). Our long-term interest is, of course, in what works best for supporting the kind of special programming that public television thrives on.''
In Washington, John B. Ford, planning associate of the National Association of Public Television Stations, reports: ''When we started we knew absolutely nothing about advertising, but we knew we had to find new ways to raise money. Philosophically, public broadcasting is divided on this question. For some stations the issue is not money but the appropriateness of advertising and its potential influence on program content. As far as this experiment goes, the early signs are promising, but it is still too soon to tell if there will be an erosion of subscribers and funding grants.''
John Jay Iselin, president and general manager of WNET, is less restrained in his optimism for the project. ''With the signing up of Chemical Bank as an 'enhanced underwriter' of 'Wall Street Week' we are more than ever encouraged with this concept for building a new revenue bridge to the private sector.''
There are still problems to be solved. For example, will copyright holders and unions continue to settle for lower pay if they see public broadcasting making huge advertising gains?