By Ossian Shine

LONDON (Reuters) - Tennis chiefs plan to adopt the NFL's Super Bowl model, by selecting fixed-venue cities in advance for their showcase Davis and Fed Cup finals.

The switch away from one of the finalists hosting the decider is part of a broader strategy aimed at developing the men's and women's international team events.

"This is all part of our mission to make the appeal of tennis broad and wide," International Tennis Federation President David Haggerty told Reuters.

Other options under consideration include a tweak of formats to reduce the length of matches, and expanding the top-tier Fed Cup competition to feature 16 nations.

Haggerty, elected president a year ago, hopes to have the new hosting system in place by 2018.

"Davis Cup is 135 nations," Haggerty said. "This is a way to unlock potential revenue which will help grassroots tennis."

Speaking at his Roehampton office, in a suburban district of south-west London, Haggerty did not name a figure cities would have to come up with to host the final, but said he thought it would be "significant".

"We're waiting for cities to distinguish themselves," he smiled. "And we'll see what it is. I don't want to prejudge what it might be."

The ITF membership will vote on the plans next August.

In American football's Super Bowl, the host city is selected well in advance, usually three-to-five years before the game.

Similarly, European soccer's governing body, UEFA, selects the host city for the Champions League final two years in advance.

PRIME BENEFITS

Haggerty said he hoped to see cities, federations and their sponsors come together to bid for 2018.

"The most likely scenario would be for two-to-three-year terms," said the American who won a four-year presidential spell in 2015.

"Right now we know who are in the finals but we don't know where it is going to be."

Croatia will host Argentina for the 2016 Davis Cup title after winning their respective semi-finals last weekend. But a host city has yet to be named.

"It is really hard to plan and get viewership and fans excited," Haggerty said of the current format. "If you have a fixed site, people can begin to plan and look ahead.

"Last year we had a fantastic final in Ghent. But the reality is, Britain could have sold out the (13,000-capacity) stadium. Belgium could have sold it out, too."

In the women's competition, Haggerty is eager to introduce an expanded Fed Cup top group, and introduce a "Final Four" format.

"We are going to spend the next nine months working with players, with our nations, talking about other possibilities, such as formats.

"Should it be in Davis Cup two out of three sets, or three out of five? It could be looking at a two-day format."

Haggerty said one of the prime benefits of the "neutral final" plan was to unlock more potential revenue.

"This can then be used to grow our mission, which is to distribute funds to grassroots tennis, especially to nations who need money for development.

"Because right now the hosting country is the one that gets all the glory, and the money. This would enable us to distribute it in a far better way to achieve our mission.

"Our mission is to make tennis broad and wide. We have 700,000 spectators that come to Davis and Fed Cup each year... about 3.6 billion people view it on TV, but it's got to be more than that.

"It's got to be bigger than that, and with a neutral final venue we can work with our broadcast partners and make it a much bigger show than just two nations that know they're playing each other.

"We can make this into a much more massive win for tennis."

(Editing by Neville Dalton)