At a time when Madison Avenue appears to be picking a fight with the nation’s TV networks, NBCUniversal says it won’t take the bait.

The Comcast-owned company in a Monday letter to ad buyers and agencies urged advertisers to tackle bigger issues than a shift in TV’s annual “upfront” ad sales marketplace, a move for which many in the advertising community are calling. The message, from Linda Yaccarino, NBCUniversal’s chairman of advertising and partnerships, urges marketers to “go even further” to make changes in how advertising is transacted at “a moment of massive cultural and structural change.”

While Yaccarino’s letter does not mention the Association of National Advertisers, the letter appears to be an effort to respond to that influential organization’s demand last week that TV networks push back the industry’s annual “upfront,” when media companies try to sell the bulk of their ad inventory to sponsors in advance of the next programming cycle. As the coronavirus pandemic forces delays in sports seasons and the production of scripted programming, and creates a severe business downturn, the ANA on Thursday enlisted top executives from companies like Bank of America and Procter & Gamble to push the upfront process to later in the year, “with the typical negotiation window occurring in the fall or early winter timeframe.”

Walt Disney, ViacomCBS, Univision and NBCU are among the companies that have said they will remain flexible this year, so as to do business with some advertisers who need more time to ascertain the needs of their business and operations.

Yaccarino did not directly address the ANA’s proposal, and with good reason: NBCU and other media companies are already having discussions with advertisers who are ready to make upfront buys in the near term, according to people familiar with the negotiations.

But she urged advertisers and agencies to commit “to a new open marketplace built on trust, radical transparency, and meaningful collaboration. Just imagine how opening up training, technology, and insights across the marketing industry could simultaneously accelerate lasting transformation and real economic recovery.”

NBCUniversal has been working to get advertisers to commit to new forms of measurement and advertising placement, so that ad campaigns might shift between both the linear TV that the company sells, as well as its digital and mobile assets.

“NBCUniversal is creating more marketing training and development resources while mapping out a new open-source technology structure—one that will streamline all advertising processes, bring measurement into the 21st century, and completely transform the way marketers transact with us,” Yaccarino said. “But we’re only one company; we need others to join us.”

NBCU has tried to prod the advertising community to adopt change in the past. In 2017, Yaccarino gathered dozens of advertisers, TV executives and digital sales chiefs in a space that one housed the now-shuttered Four Seasons restaurant to discuss such topics as measurement, ad effectiveness, and new advertising standards. Some attendees at the time were impressed by the roster of guests, but felt NBCU promised more than it delivered., The day was full of panel discussions, but was unable to deliver concrete recommendations to move the industry to a new consensus on many of its most pressing issues.

Yaccarino in her current note called for advertisers and networks to try again. “Inevitably, this open marketplace will require new alliances, partnerships, business models, and maybe even some strange bedfellows,” she said. “And none of that should scare us; it should liberate us to do whatever this moment requires.”