(Reuters) - A merger between Honda ( HMC ) and Nissan ( NSANF ) would not come with quick gains, as the automakers would first need to align their strategies while overlapping regional markets would limit the sales benefits, S&P analysts said on Wednesday.

While the potential deal would result in a $54 billion automotive company, the world's third largest, any benefits for its credit outlook would come with a delay, they wrote in a research note.

"We ... believe it will be difficult for them to produce significant effects quickly through expanding the scope of their collaboration to include batteries, software, and autonomous driving," S&P analysts said, but added the eventual impact on their creditworthiness would be significant.

A merger would likely have a negative impact Honda's ( HMC ) standalone credit outlook, while it should positively affect that of Nissan ( NSANF ), they added.

They also noted that while Honda ( HMC ) and Nissan ( NSANF ) have different development strategies, they operate in similar regional markets, most notably in North America, China and Japan.

"They therefore don't complement each other much in terms of regional sales," the analysts said.