* PNB to study IFCI stake sale plan closely; bid only in consortium.
* Mumbai world's 4th most expensive office mkt.
* Inflation at 8.1% for week ended May 17
* Indian economy boomed at 9% in 2007-08
* Chidambaram says don't know if inflation peaked at current 8.10%
* Oil ministry moots 3 fuel price hike options; decision likely Sat