In this case A along with B,C & D would be considered as PAC and their stage-wise disclosures under existing SEBI (SAST) Regulations, 1997 would be as under :
1) Acquisition is between 5% to 14% of shares or voting rights à To disclose at every stage from 5%, 10% or 14% of their shareholding to the target company and the Stock Exchanges within 2 days of acquisition or receipt of intimation of allotment of shares.
2) Holding more than 15% shares or voting rights of target company à annual disclosures the target company within 21 days from the financial year ending March 31 as well as the record date fixed for the purpose of dividend declaration, disclose every year his aggregate shareholding to the target company.
You must be aware that SEBI (Substantial Acquisition of Shares and Takeovers) Regulations, 2011 has been pronounced in the last week which will replace the existing Takeover (SAST) Regulations, 1997 w.e.f. October 22, 2011. The compliance in respect of new regulation must to be looked into for your qs.
Regards
DS