Broom scored an unbeaten 124 for Otago in its win against the Northern Knights on Sunday, his second ton of the one-day season.
His latest big knock is his fifth one-day century for Otago and he has now scored the most one-day centuries for Otago in the 50-over version of the game.
He has pulled ahead of Craig Cumming, who scored four hundreds for Otago.
Otago coach Nathan King said Broom was playing well in all three facets of the game this season and had batted beautifully in the game against Northern Knights in Whangarei.
He shared a record partnership with Anaru Kitchen for the second wicket against Northern and combined with Mark Craig at the end to accelerate the run rate as the side made it through to 298 for six wickets.
Broom's highest one-day score for Otago is 164 which he made on December 31, 2009 against Canterbury at Aorangi Oval in Timaru.
He made 123 against Northern Districts, again in Whangarei on January 27, 2011.
He then backed that up three days later with an unbeaten 116 against Auckland at Colin Maiden Oval.
He scored 101 in the opening game of the Ford Trophy against Auckland in Alexandra last month.
The side lost that game but managed to get up against the Northern Knights to record its first victory for the season.
Broom came back to Otago this season after a two seasons back at his home province of Canterbury.
The 32-year-old also scored a century for Canterbury against Wellington in January last year.
Broom has played 22 one-day internationals for New Zealand, the most recent of those in 2010, and his highest score is 71, made against Bangladesh in Napier in 2010.
The right-hander is unlikely to play for New Zealand again as he has signed for English county side Derbyshire and will play as a local player in the English county competition this year, having qualified through his father, Dick, being born in England.
He will become an import player for Otago when he returns to the province next season.
