Fitch Ratings lowered its long-term issuer default rating on Washington Prime Group Inc. and its operating partnership Washington Prime Group LP to BB- from BB+, with a negative outlook.

The rating agency also lowered the regional mall real estate investment trust's long-term preferred rating to B/RR6 from BB- and downgraded the long-term senior unsecured ratings to BB/RR2 from BB+/RR4.

Fitch said the downgrade is attributed to higher leverage as the REIT continued to see weak operating performance amid the shift in retail distribution toward e-commerce and omnichannels. Weak secured mortgage availability for class B malls and deterioration in the REIT's unencumbered asset coverage of unsecured debt also contributed to the downgrade, Fitch added.

The negative outlook factors in the agency's view that the company will face pressure on its capital access and cash flows amid expectations for operating performance trends and redevelopment requirements to continue in the near-to-medium term.