US buyers currently number "in the tens" of the entire debenture list of about 2,500, which is largely Britain-based, Brook said.
"So it's a very small proportion," he said. "We're not reliant on the US but we just wanted to see if we could raise a little bit more awareness over there. If we went into the hundreds it would be nice."
Centre Court debentures, which are sold every five years, were first marketed in 1920 to pay for the construction of what's become the world's most famous tennis court.
This year's Centre Court debenture issue is 80 per cent more expensive than the previous one, when they were sold for 27,750 pounds each in the five years from 2011. The All England Club raised 60 million pounds at the time.
Around half a million tennis fans visit the Wimbledon championships each summer in southwest London. Unlike tickets from the heavily oversubscribed public ballot, debentures are freely transferable.
One debenture valid for the 2011-2015 period was sold for 96,250 pounds in January, according to the Wimbledon website. Historically, preference has been given to existing debenture-holders for the next round, it said.
Brook said this year's price increase was partly because of the economic recovery as well as Andy Murray winning the singles title last year. He was the first man from Britain to do so since Fred Perry in 1936.
Wimbledon is planning a retractable roof over No. 1 Court by 2019. Centre Court has had such a roof since 2009 after years of struggles with rain delays. It will also build three new courts north of No. 1, new player accommodation and landscaping that seeks to give fans the experience of "tennis in an English garden," it said at a press conference on Tuesday.
This year's tournament will be held June 23 through July 6.
- Bloomberg