Dubai-based engineering and consulting firm Sidara on Wednesday raised its proposed takeover offer for John Wood Group for the third time, saying that was its "final offer" for the British oilfield services and engineering company.

The latest proposal for a cash offer of 230 pence apiece would value Wood Group at about 1.59 billion pounds ($2.03 billion), representing a premium of 52% to its closing share price before the first bid was made.

Wood said it was evaluating the proposal.

Wood has not engaged with Sidara since the first approach was made, Sidara said.

"Sidara does not believe that its proposal can be progressed unless the board of Wood engages with Sidara and an extension of the deadline is granted," it added.

Sidara has until June 5 to make a formal offer or walk way.

Shares in Wood Group were down 2.9% at 1326 GMT.

Last year, the Scotland-based company rejected multiple offers from U.S.-based Apollo Global Management, forcing the private equity company to abandon takeover plans.

Sidara's proposals follow activist shareholder Sparta Capital Management's letter to Wood last month, pushing it to consider either selling itself or to reconsider its UK listing.

Wood, which provides consultation, management of assets and engineering services for the energy and materials sector, operates in more than 60 countries.

($1 = 0.7846 pounds)

(Reporting by Prerna Bedi and Eva Mathews in Bengaluru; Editing by Shailesh Kuber and Jane Merriman)