...- S&P Global Ratings revised its commodity price deck lower, which we expect will cause Summit Midstream Partners L.P. (SMLP) to realize lower adjusted EBITDA and volume flow levels than what we had previously forecast. We now forecast SMLP's adjusted leverage to be 5.75x-6.25x over the next 24 months. - As a result, we are lowering our issuer credit rating on SMLP to 'B' from 'B+'. The outlook is negative. - At the same time, we are lowering our issue-level ratings on Summit Midstream Holdings LLC senior unsecured debt to 'B-', reflecting our recovery expectation of '5' modest (10%-30%; rounded estimate: 25%) recovery in the event of a default. We are also lowering the preferred stock rating to '###' from '###+'. - The negative outlook on SMLP reflects our expectation of elevated leverage metrics over the next 24 months. The company could face refinancing challenges, given the approximately $975 million of debt maturities coming due in 2022 (approximately $677 million drawn as of 12/31/19...