The Supreme Court judgment directing the government to halt the divestment of Bharat Petroleum Corporation Ltd and Hindustan Petroleum Corporation Ltd, and asking it to go back to Parliament to seek consensus for the sale came as a shock for the divestment ministry, the Bharatiya Janata Party, Divestment Minister Arun Shourie and the markets.

Here is the chronological order of events leading to Tuesday's developments:

October 2001

• Divestment ministry circulates an internal paper proposing 25% equity sale in HPCL and 30% in BPCL to strategic investors.
• Also suggests immediate sale of equity in ONGC, GAIL and IOC.
• Petroleum ministry suggests vertical integration of IOC, ONGC, GAIL and IPCL.

December 2001

• Divestment ministry targets HPCL, BPCL sale in 2002-03.

February 2002

• CCD approves in principle strategic sale of government equity in HPCL and BPCL. Says PSUs will be kept out of the bidding process.
• No statement on whether ONGC or GAIL could bid for HPCL & BPCL.
• Divestment ministry in favour of barring all PSUs, but only IOC to be kept out on Ram Naik's insistence.

March 2002

• CCD drops the issue as Naik proposes a meet with Arun Shourie to finalise the sale process.

July 2002

• CCD asks divestment ministry to draw up a schedule for completing sale of HPCL and BPCL, among other PSUs.
• Petroleum ministry says matter cannot be finalised before its views are considered.

September 2002

• CCD decides that all PSUs and multi-state co-operatives will be barred from bidding, but in special cases, the administrative ministry can make a case for allowing certain PSUs to bid.

December 2002

• CCD defers decision on sale of HPCL & BPCL pending Attorney-General's decision on requirement of parliamentary approval.

January 2003

• Attorney-General says parliamentary approval not required to sell the two companies.

January 26, 2003

• CCD decides to offload 34.01% to a strategic partner in HPCL, but turns down a proposal on strategic sale in BPCL. BPCL to have a public float of 35.2%, with 25.2% ADRs and 10% in domestic market.
• ONGC barred from bidding for HPCL.

March 2003

• HSBC Securities appointed as adviser for sale of HPCL.

March 13, 2003

• Centre for Public Interest Litigation files PIL against divestment.

June 2003

• DSP Merrill Lynch, ICICI Securities and UBS-Warburg appointed as joint global co-ordinator-cum-adviser for BPCL float.

July 2003

• Oil Sector Officers' Association and other unions file PILs against sale of HPCL and BPCL.

August 28, 2003

• Due diligence for HPCL begins.

September 16, 2003

• Supreme Court rules parliamentary approval necessary for HPCL and BPCL selloff.