BMW anybody? Carmakers to gain most from weak euro

European carmakers (.SXAP) and chemical (.SX4P) and tourism companies stand to benefit most from the weakening euro, according to Moody's, while the airline sector looks set to be worst hit.

The credit ratings provider said the falling euro (EUR=) would be "positive for companies that have the majority of their cost bases in the euro area with significant sales to regions outside it."

These included German premium auto manufacturers such as BMW (BMW-DE) , Daimler (DAI-DE) and Volkswagen (VOW3-DE) , which export a large share of their production to external markets including the U.S.

Germany companies were also seen as the major beneficiaries in the chemicals sector, with Moody's naming K&S (SDF-DE) and Lanxess (LXS-DE) as those most likely to gain, given that potash and synthetic rubber are "typically U.S. dollar markets."

Moody's added that the hotels and tourism sector would also receive a boost, due to increased demand as euro area destinations became cheaper for travelers from overseas.

Read More Weak euro boosts region's business growth

Since the start of last year, the euro has fallen by around 12.5 percent again U.K. sterling (EURGBP=) to £0.73 on Wednesday. It has slipped 19 percent against the U.S. dollar to $1.11.