Southwest Gas Holdings Inc.'s (SWX) subsidiary Centuri Group Inc. has completed its acquisition of Riggs Distler&Co. Inc. We believe this acquisition will increase the company's business risk and weaken its financial measures. We downgraded SWX to 'BBB-' from 'BBB+' and its subsidiary Southwest Gas Corp. (SWG) to 'BBB' from 'A-' and removed all of our ratings on the companies from CreditWatch, where we placed them with negative implications on June 29, 2021. At the same time, we lowered our issue-level rating on SWG's senior unsecured debt to 'BBB' from 'A-'. The stable outlook reflects our expectation SWX's construction services business will account for about 40% of its consolidated EBITDA and that its consolidated funds from operations (FFO) to