Here's another possible approach, in case you ever have to do (many) more columns 🙂 :
DELETE FROM dbo.trefClientShares
WHERE
CASE WHEN intLMid IS NULL THEN 1 ELSE 0 END +
CASE WHEN intMLid IS NULL THEN 1 ELSE 0 END +
CASE WHEN intISid IS NULL THEN 1 ELSE 0 END +
CASE WHEN intFRid IS NULL THEN 1 ELSE 0 END >= 3
SQL DBA,SQL Server MVP(07, 08, 09) A socialist is someone who will give you the shirt off *someone else's* back.