Hope this too will work ,but while coming to performace related point of view hope this query will degrade.I have posted this because it may help someone in future.

SELECT

distinct c.grp,sum(amount) amt,

ledger = REPLACE(

( SELECT

ledger AS [data()]

FROM

sample s

WHERE

s.grp = c.grp

FOR XML PATH ('')

), ' ', ',')

FROM

sample c group by c.grp

Thanks

Chandru