COLOMBO, Oct 26 (Reuters) - Sri Lanka's central bank said on Tuesday it was expecting investments of around $1.1 billion from deals being made in the real estate, ports and energy sectors to help top up the country's flagging foreign exchange reserves.

The central bank also said it was in talks with the Reserve Bank of India, the People's Bank of China and several Middle Eastern Central Banks for finalizing foreign currency swap arrangements.

However, it did not give a definitive timeline on when these currency swap agreements would be settled.

"We have to wait and see how fast some of these key arrangements are going to materialise," ICRA Lanka Head of Research Lalinda Sugathadasa said.

"The government should clearly lay out a timeline for these expected inflows to send a strong signal to investors."

Sri Lanka's reserves had dropped to $2.5 billion by the end of September. On Oct. 1, Sri Lanka unveiled a six-month roadmap for putting the economy back on track and calming investor worries about a possible default.

The island nation has to repay a $500 million international sovereign bond in January and another $1 billion bond maturing in July. On Oct. 11, the central bank shelved its plans to buy back those sovereign bonds because of a lack of interest from bond holders to sell at discounted prices.

Separately, Finance Ministry sources told Reuters the government had received proposals from three banks and two investment houses on Oct. 5 to raise a syndicated loan for an unspecified amount.

The central bank also said the government is processing a long-term loan offer of $1.5 billion from a "foreign government affiliated agency" but did not give details.

It also added there was progress on talks with India about a credit line of $500 million and a long-term loan facility of about $3.6 billion. (Reporting by Uditha Jayasinghe in Colombo; Writing by Chandini Monnappa in Bengaluru; Editing by Krishna Chandra Eluri)