Secretaries to Maskeliya Plantations said in a stock exchange filing that the RPC group was holding talks on the possible sale of its subsidiary RPC Management Service, the parent firm of the tea company.
Maskeliya Plantations suffered the biggest fall of the day, losing the gains the day before, to end down 18.12 percent (6.25 rupees) at 28.25 rupees.
Maskeliya was the most actively traded share, and most active in volume terms with 931,900 shares traded, followed by its parent Richard Pieris & Co.
RPC closed down 75 cents at 47 rupees although it went up to 50.50 rupees during the day's trading with 543,300 shares done.
The All Share Price Index fell 2.23 percent (48.01 points) to 2,107.18 while the more liquid Milanka plunged 3.14 percent (75.97 points) to 2,342.73.
Turnover was 248 million rupees.
"Large caps brought down the market," said Mohan Thangarajah of First Guardian Equities.
Sri Lanka stocks fell in a day of global turmoil which saw, central bankers rushing to give assurances to depositors and Middle Eastern stocks took an unprecedented beating.
Dialog Telekom sank to an all-time low of 7.50 rupees before recovering to close at 7.75 rupees, down 3.12 percent from the previous close.
John Keells Holdings fell 7.51 percent or 6.50 rupees to 80 rupees, Sri Lanka Telecom came down 3.53 percent (1.50 rupes) to end at 41 rupees and Commercial Bank also fell, down 3.37 percent (3.50 rupees) to 100.25 rupees.
Thangarajah said Maskeliya and its parent Richard Pieris & Co fell when it became known no sale of the plantations firm was imminent.