UBS has downgraded shares of Carnival Corp to neutral from buy, based on lower earnings expectations for next year.

The investment bank has also lowered its 2020 price target to $47 from $60 as a result of further weakening in the European market and two years of flat earnings per share (EPS). UBS also cut its EPS estimate for next year by $0.54 to $4.26 based, on on expectations of lower yields.

"While CCL is currently trading below historical valuation multiples, we see no clear catalyst for upside near-term given a lack of earnings growth," analyst Robin Farley wrote in a clients' note, referring to the company by its ticker symbol.

She said the Miami cruiseship giant's New York-listed shares are trading at a multiple of 10 times EPS, compared to a multiple of 14 or 15 times this figure in recent years. That's because the company's EPS guidance assumes no growth this year.

The same could hold true for 2020, Farley wrote.

"While we believe CCL remains a well-managed company with strong brands and growth in the longer term, external forces have impacted and are likely to continue to impact CCL’s near-term earnings outlook," she wrote.

Negative factors beyond the Arnold Donald-led company's control include Hurricane Dorian in North America and tanker attacks in the Arabian Gulf, she noted.