These adverse impacts were partially offset by the favourable impact of improved equity markets of $306 million and increased interest rates of $206 million on the company's results." Downgrading Its weak results contributed to a downgrading this April by Standard & Poor's of Sun Life's long-term counterparty credit and financial strength rating to AA minus from AA. "We believe Sun Life Financial Inc.'s 2010 after-tax operating earnings will come in below our expectation and that the U.S. investment portfolio will show further asset impairments, which will add pressure to the group's capital," said S&P's analysis. "Based on weaker-than-expected operating earnings and expected future pressure on capital, we have lowered the ratings on SLF and its North American subsidiaries by one notch. The outlook on SLF's North American subsidiaries is stable, and the outlook on SLF is negative."