Colin Munro has passed 500 runs in the Plunket Shield this season with Auckland but his side have lost ground in the leadership battle after going down by four wickets to Otago in Dunedin.

Worcestershire's NatWest T20 Blast player for 2015 is lying third in the Auckland batting averages in the four-day competition with 502 runs from 13 innings at an average of 38.61.

He has scored one century and three fifties, has a strike rate of 89.32 and has struck 18 of his team's 38 sixes in the Plunket Shield.

But Auckland have dropped down to joint third spot after collecting just four points to Otago's 19 points.

They are level on 70 points with Northern District with Otago one point better off and current title holders Canterbury leading the way on 84 points.

Munro experienced a rare double failure against Otago, scoring three and 14, as Auckland set Otago a target of 256 which they knocked off in only 38.3 overs.

He held onto two first innings catches including one to dismiss top scorer Michael Bracewell for 126.

Auckland will next be in action against visiting Wellington from March 17-20 and have a total of three more games remaining.

Munro will then link up with Worcestershire in mid May in time for the opening T20 Blast match away to Birmingham Bears on May 22.

He finished as the county's second highest scorer in the competition behind skipper Daryl Mitchell in last season's run to the quarter-finals.