Credit rating agencies examining the state government and University of Minnesota maintained their high ratings this week ahead of the sale of new bonds and refinancing of others, including the ones that paid for the TCF Bank Stadium.

But the university encountered a small bump when Standard & Poor’s, after keeping the institution at an AA credit rating, changed its outlook on the institution from “stable” to “negative.” It cited the growing level of debt at the university and “recent weakness in financial operations.”

The change is a cautionary signal for the university, though it is unlikely to have a financial effect.

The U’s chief financial officer, Richard Pfutzenreuter, said he was surprised by the move but didn’t think it would affect the interest rate the institution will pay on a $10 million bond sale expected next week.

“When we’re actually in the market next week, I bet we’re oversubscribed,” he said.

With demand high, bond issuers are winding up paying relatively low rates. Minnetonka-based UnitedHealth Group Inc. sold more than $10.5 billion in a series of offers on July 20, with yields narrowing through the day.

Over the next two years, the U’s bond debt will rise about 8 percent to nearly $1.5 billion. It plans to issue about $260 million in new bonds and repay about $140 million in an existing one during that time.

Moody’s maintained an Aa1 rating, its second highest, for the U and kept its outlook stable. Both S&P and Moody’s will take another look before the U returns to the debt market in December.

The state, meanwhile, got a bump up this week when S&P lifted its outlook to “positive” from “stable.” Myron Frans, the Minnesota Management and Budget commissioner, said the state hadn’t seen a rating change since 2013.

“This is the first major progression since then,” he said.

Though he welcomed the move, Frans said it was difficult to assess the impact it may have had on the state’s sale of $1 billion in bonds on Wednesday. There is a strong market now for bonds, particularly from highly rated issuers like the state and university.

Demand was solid for the state’s issues, the largest of which had an interest rate of 2.93 percent, which Frans said was the closest the state had come to the low level of interest paid by the highest rated, AAA bond issuers.

The state of Minnesota has an AA+ rating from S&P and an Aa1 from Moody’s, just below the agencies’ AAA ratings.

Among the issues, the state and university are undertaking a series of transactions that refinance the 2006 bonds that paid for the university’s football stadium. Frans said the state will save $40 million in interest payments as a result of the refinancing.