(Reuters) -Assura said on Monday that it would consider a 1.61 billion pound ($2.1 billion) offer from U.S. private equity group KKR and Stonepeak Partners, pushing shares of the British healthcare real estate investment trust up 14%.

Assura's shares jumped to about 46.5 pence, still just over half of their peak price of 88 pence in 2020 and under the latest offer of 49.4 pence per share.

The company said its board had decided to engage in discussions with the consortium and allow it to complete a limited period of confirmatory due diligence.

It added that it "would be minded" to recommend any final offer made on those terms.

Assura has rejected four previous indicative, non-binding proposals from a separate consortium of KKR and pension fund Universities Superannuation Scheme (USS), the last of which proposed 48 pence per share in February.

Monday's offer from KKR and New York-headquartered investment firm Stonepeak is at a 31.9% premium to the closing share price on February 13, a day before the KKR-USS proposal was made, and a 21.3% premium to Friday's close.

Following the rejection of the February offer, a source familiar with the situation told Reuters that any future attempt from KKR would likely be an independent one as USS had backed out.

Assura also said on Monday that it rejected a non-binding, all-share merger proposal from Primary Health Properties ( PHPRF ) that valued Assura shares at 43 pence each.

It said the possible cash offer from KKR and Stonepeak was more attractive, adding that PHP has until April 7 to make a firm offer for Assura under British takeover rules.

PHP did not immediately respond to Reuters' request for comment.

As of last September, Assura ran more than 600 properties with an investment value of about 3.2 billion pounds and counted among its customers Britain's National Health Service.

($1 = 0.7747 pounds)