At a time when newspapers nationwide are finding it increasingly difficult to maintain readership, the Star Tribune and the Pioneer Press have both experienced recent Sunday circulation growth.

According to the Audit Bureau of Circulations, the Star Tribune's Sunday circulation averaged 504,616 for the six-month period that ended on September 30-up 5.7 percent from the same period last year. Meanwhile, the Pioneer Press' Sunday circulation averaged 247,188, up 0.21 percent from the same time last year. Both local newspapers announced the gains on Monday.

Weekdays are a bit of a different story. The Minneapolis-based Star Tribune averaged 297,478 in weekday circulation during the six months that ended in September-representing a 2.3 percent decrease from the same time frame last year but a slight increase from the six-month period that ended in March. The Pioneer Press' weekday circulation, meanwhile, went up 0.28 percent to 185,736.

Star Tribune Publisher and CEO Michael J. Klingensmith attributed his paper's Sunday growth to the success of its early Sunday edition-which was launched in October 2009. That edition replaced the paper's Saturday newsstand edition.

Klingensmith added that the Star Tribune-the nation's eighth-largest newspaper-has improved its sales efforts by shifting from telemarketing to direct sales and has put more of a focus on improving customer service, which has contributed to higher retention rates.

The Pioneer Press on Monday touted the fact that it has reported Sunday circulation growth for 10 consecutive reporting periods and weekday growth for eight. The St. Paul-based paper said that Sunday circulation increases are greatest in three major east-metro counties-Ramsey, Dakota, and Washington-that have long been its stronghold.

The Pioneer Press made the news last week when it announced a partnership to run business operations for the Twin Cities print edition of the satirical weekly publication The Onion and its sister publication, the A.V. Club.