Mayor Michael Bloomberg has formally asked the state to approve his choice for chancellor, publishing executive Cathie Black.

Because Black lacks the education credentials legally required to be chancellor, State Education Commissioner David Steiner must grant Black a waiver allowing her to take the post. State law allows the commissioner to waive the requirements for chancellor candidates who are “exceptionally qualified.”

Black has almost no experience in public school systems in New York or elsewhere, and the mayor’s surprise appointment of her last week has caused an uproar from critics who believe the chancellor should have experience in schools.

In a six-page letter to Steiner released this evening, Bloomberg makes the argument that Black’s extensive experience in the magazine publishing world, including fifteen years as the head of Hearst Magazines, will translate into the skills she will need to run the nation’s largest public school system.

For example, Bloomberg argues that Black’s experience starting a digital media unit at Hearst shows that she can help schools teach students more technologically advanced skills and improve the way that schools track and improve student progress. He also contends that because Black saw Hearst through financial challenges that precipitated layoffs and the closure of struggling magazines, she will be prepared to handle the steep budget reductions city schools will likely face in the next year.

The next step will be for Steiner to appoint a panel that will review Bloomberg’s case for Black. The panel will issue a non-binding recommendation to Steiner, who will then announce his decision. It’s not clear when Steiner will appoint his panel or when he will make his final decision.

We will have much more on the mayor’s formal case for Black tomorrow. (Tonight we are throwing a party!) But in the meantime, the mayor’s letter to Steiner is below. Please share your observations on the letter in the comments!